From 5643ef05bc81e4a840e9456f4406a769abbe1392 Mon Sep 17 00:00:00 2001
From: Roberto Vidal <vidal.roberto.j@gmail.com>
Date: Fri, 30 Oct 2020 14:39:28 +0100
Subject: [PATCH 001/126] fix: more unique temp_file

---
 src/exercise.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/exercise.rs b/src/exercise.rs
index b07d7a11..283b2b90 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -11,10 +11,15 @@ const I_AM_DONE_REGEX: &str = r"(?m)^\s*///?\s*I\s+AM\s+NOT\s+DONE";
 const CONTEXT: usize = 2;
 const CLIPPY_CARGO_TOML_PATH: &str = "./exercises/clippy/Cargo.toml";
 
-// Get a temporary file name that is hopefully unique to this process
+// Get a temporary file name that is hopefully unique
 #[inline]
 fn temp_file() -> String {
-    format!("./temp_{}", process::id())
+    let thread_id: String = format!("{:?}", std::thread::current().id())
+        .chars()
+        .filter(|c| c.is_alphanumeric())
+        .collect();
+
+    format!("./temp_{}_{}", process::id(), thread_id)
 }
 
 // The mode of the exercise.

From 0c12fa31c57c03c6287458a0a8aca7afd057baf6 Mon Sep 17 00:00:00 2001
From: sazid <sazidozon@gmail.com>
Date: Mon, 26 Oct 2020 12:54:32 +0600
Subject: [PATCH 002/126] feat: Add Vec exercises

---
 exercises/collections/README.md | 20 +++++++++++++++++
 exercises/collections/vec1.rs   | 25 ++++++++++++++++++++++
 exercises/collections/vec2.rs   | 38 +++++++++++++++++++++++++++++++++
 info.toml                       | 30 ++++++++++++++++++++++++++
 4 files changed, 113 insertions(+)
 create mode 100644 exercises/collections/README.md
 create mode 100644 exercises/collections/vec1.rs
 create mode 100644 exercises/collections/vec2.rs

diff --git a/exercises/collections/README.md b/exercises/collections/README.md
new file mode 100644
index 00000000..9ded29a0
--- /dev/null
+++ b/exercises/collections/README.md
@@ -0,0 +1,20 @@
+### Collections
+
+Rust’s standard library includes a number of very useful data
+structures called collections. Most other data types represent one
+specific value, but collections can contain multiple values. Unlike
+the built-in array and tuple types, the data these collections point
+to is stored on the heap, which means the amount of data does not need
+to be known at compile time and can grow or shrink as the program
+runs.
+
+This exercise will get you familiar with two fundamental data
+structures that are used very often in Rust programs:
+
+* A *vector* allows you to store a variable number of values next to
+  each other.
+* A *hash map* allows you to associate a value with a particular key.
+  You may also know this by the names *map* in C++, *dictionary* in
+  Python or an *associative array* in other languages.
+
+[Rust book chapter](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)
diff --git a/exercises/collections/vec1.rs b/exercises/collections/vec1.rs
new file mode 100644
index 00000000..ac3d9f1a
--- /dev/null
+++ b/exercises/collections/vec1.rs
@@ -0,0 +1,25 @@
+// vec1.rs
+// Your task is to create a `Vec` which holds the exact same elements
+// as in the array `a`.
+// Make me compile and pass the test!
+// Execute the command `rustlings hint collections1` if you need hints.
+
+// I AM NOT DONE
+
+fn array_and_vec() -> ([i32; 4], Vec<i32>) {
+    let a = [10, 20, 30, 40]; // a plain array
+    let v = // TODO: declare your vector here with the macro for vectors
+
+    (a, v)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_array_and_vec_similarity() {
+        let (a, v) = array_and_vec();
+        assert!(a.iter().zip(v.iter()).all(|(x, y)| x == y));
+    }
+}
diff --git a/exercises/collections/vec2.rs b/exercises/collections/vec2.rs
new file mode 100644
index 00000000..ec6cfc00
--- /dev/null
+++ b/exercises/collections/vec2.rs
@@ -0,0 +1,38 @@
+// vec2.rs
+// A Vec of even numbers is given. Your task is to complete the loop
+// so that each number in the Vec is multiplied by 2.
+//
+// Make me pass the test!
+//
+// Execute the command `rustlings hint collections2` if you need
+// hints.
+
+// I AM NOT DONE
+
+fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
+    for i in v.iter_mut() {
+        // TODO: Fill this up so that each element in the Vec `v` is
+        // multiplied by 2.
+    }
+
+    // At this point, `v` should be equal to [4, 8, 12, 16, 20].
+    v
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_vec_loop() {
+        let v: Vec<i32> = (1..).filter(|x| x % 2 == 0).take(5).collect();
+        let ans = vec_loop(v.clone());
+
+        assert_eq!(
+            ans,
+            v.iter()
+                .map(|x| x * 2)
+                .collect::<Vec<i32>>()
+        );
+    }
+}
diff --git a/info.toml b/info.toml
index 2d0abdb1..56605a7b 100644
--- a/info.toml
+++ b/info.toml
@@ -370,6 +370,36 @@ its internal structure (the `fruits` and `veggies` modules and
 associated constants). It's almost there except for one keyword missing for
 each constant."""
 
+# COLLECTIONS
+
+[[exercises]]
+name = "collections1"
+path = "exercises/collections/vec1.rs"
+mode = "test"
+hint = """
+In Rust, there are two ways to define a Vector.
+
+1. One way is to use the `Vec::new()` function to create a new vector
+  and fill it with the `push()` method.
+
+2. The second way, which is simpler is to use the `vec![]` macro and
+  define your elements inside the square brackets.
+
+Check this chapter: https://doc.rust-lang.org/stable/book/ch08-01-vectors.html
+of the Rust book to learn more.
+"""
+
+[[exercises]]
+name = "collections2"
+path = "exercises/collections/vec2.rs"
+mode = "test"
+hint = """
+Hint 1: `i` is each element from the Vec as they are being iterated.
+  Can you try multiplying this?
+
+Hint 2: Check the suggestion from the compiler error ;)
+"""
+
 # MACROS
 
 [[exercises]]

From 633c00cf8071e1e82959a3010452a32f34f29fc9 Mon Sep 17 00:00:00 2001
From: sazid <sazidozon@gmail.com>
Date: Mon, 26 Oct 2020 18:08:48 +0600
Subject: [PATCH 003/126] feat: Add HashMap exercises

---
 exercises/collections/hashmap1.rs | 46 +++++++++++++++++
 exercises/collections/hashmap2.rs | 83 +++++++++++++++++++++++++++++++
 info.toml                         | 22 ++++++++
 3 files changed, 151 insertions(+)
 create mode 100644 exercises/collections/hashmap1.rs
 create mode 100644 exercises/collections/hashmap2.rs

diff --git a/exercises/collections/hashmap1.rs b/exercises/collections/hashmap1.rs
new file mode 100644
index 00000000..b1dc0bbd
--- /dev/null
+++ b/exercises/collections/hashmap1.rs
@@ -0,0 +1,46 @@
+// hashmap1.rs
+// A basket of fruits in the form of a hash map needs to be defined.
+// The key represents the name of the fruit and the value represents
+// how many of that particular fruit is in the basket. You have to put
+// at least three different types of fruits (e.g apple, banana, mango)
+// in the basket and the total count of all the fruits should be at
+// least five.
+//
+// Make me compile and pass the tests!
+//
+// Execute the command `rustlings hint collections3` if you need
+// hints.
+
+// I AM NOT DONE
+
+use std::collections::HashMap;
+
+fn fruit_basket() -> HashMap<String, u32> {
+    let mut basket = // TODO: declare your hash map here.
+
+    // Two bananas are already given for you :)
+    basket.insert(String::from("banana"), 2);
+
+    // TODO: Put more fruits in your basket here.
+
+    basket
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn at_least_three_types_of_fruits() {
+        let basket = fruit_basket();
+        assert!(basket.len() >= 3);
+    }
+
+    #[test]
+    fn at_least_five_fruits() {
+        let basket = fruit_basket();
+        assert!(basket
+            .values()
+            .sum::<u32>() >= 5);
+    }
+}
diff --git a/exercises/collections/hashmap2.rs b/exercises/collections/hashmap2.rs
new file mode 100644
index 00000000..7e25be7c
--- /dev/null
+++ b/exercises/collections/hashmap2.rs
@@ -0,0 +1,83 @@
+// hashmap2.rs
+
+// A basket of fruits in the form of a hash map is given. The key
+// represents the name of the fruit and the value represents how many
+// of that particular fruit is in the basket. You have to put *MORE
+// THAN 11* fruits in the basket. Three types of fruits - Apple (4),
+// Mango (2) and Lichi (5) are already given in the basket. You are
+// not allowed to insert any more of these fruits!
+//
+// Make me pass the tests!
+//
+// Execute the command `rustlings hint collections4` if you need
+// hints.
+
+// I AM NOT DONE
+
+use std::collections::HashMap;
+
+#[derive(Hash, PartialEq, Eq)]
+enum Fruit {
+    Apple,
+    Banana,
+    Mango,
+    Lichi,
+    Pineapple,
+}
+
+fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
+    let fruit_kinds = vec![
+        Fruit::Apple,
+        Fruit::Banana,
+        Fruit::Mango,
+        Fruit::Lichi,
+        Fruit::Pineapple,
+    ];
+
+    for fruit in fruit_kinds {
+        // TODO: Put new fruits if not already present. Note that you
+        // are not allowed to put any type of fruit that's already
+        // present!
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn get_fruit_basket() -> HashMap<Fruit, u32> {
+        let mut basket = HashMap::<Fruit, u32>::new();
+        basket.insert(Fruit::Apple, 4);
+        basket.insert(Fruit::Mango, 2);
+        basket.insert(Fruit::Lichi, 5);
+
+        basket
+    }
+
+    #[test]
+    fn test_given_fruits_are_not_modified() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        assert_eq!(*basket.get(&Fruit::Apple).unwrap(), 4);
+        assert_eq!(*basket.get(&Fruit::Mango).unwrap(), 2);
+        assert_eq!(*basket.get(&Fruit::Lichi).unwrap(), 5);
+    }
+
+    #[test]
+    fn at_least_five_types_of_fruits() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        let count_fruit_kinds = basket.len();
+        assert!(count_fruit_kinds == 5);
+    }
+
+    #[test]
+    fn greater_than_eleven_fruits() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        let count = basket
+            .values()
+            .sum::<u32>();
+        assert!(count > 11);
+    }
+}
diff --git a/info.toml b/info.toml
index 56605a7b..c52702f7 100644
--- a/info.toml
+++ b/info.toml
@@ -400,6 +400,28 @@ Hint 1: `i` is each element from the Vec as they are being iterated.
 Hint 2: Check the suggestion from the compiler error ;)
 """
 
+[[exercises]]
+name = "collections3"
+path = "exercises/collections/hashmap1.rs"
+mode = "test"
+hint = """
+Hint 1: Take a look at the return type of the function to figure out
+  the type for the `basket`.
+
+Hint 2: Number of fruits should be at least 5. And you have to put
+  at least three different types of fruits.
+"""
+
+[[exercises]]
+name = "collections4"
+path = "exercises/collections/hashmap2.rs"
+mode = "test"
+hint = """
+Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this.
+
+Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value
+"""
+
 # MACROS
 
 [[exercises]]

From 535a8c82432b68b83cca3e8a42a7c9e26a09c6cd Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 30 Oct 2020 19:29:36 +0000
Subject: [PATCH 004/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index a618abb5..81962273 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-65-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-67-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️ [![Build status](https://badge.buildkite.com/7af93d81dc522c67a1ec8e33ff5705861b1cb36360b774807f.svg)](https://buildkite.com/mokou/rustlings)
@@ -231,6 +231,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://github.com/AnnikaCodes"><img src="https://avatars3.githubusercontent.com/u/56906084?v=4" width="100px;" alt=""/><br /><sub><b>Annika</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAnnikaCodes" title="Reviewed Pull Requests">👀</a></td>
     <td align="center"><a href="https://darnuria.eu"><img src="https://avatars1.githubusercontent.com/u/2827553?v=4" width="100px;" alt=""/><br /><sub><b>Axel Viala</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=darnuria" title="Code">💻</a></td>
+    <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
   </tr>
 </table>
 

From 51631f4c2e4246ddfa6be07a00cf597f51bca647 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 30 Oct 2020 19:29:37 +0000
Subject: [PATCH 005/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 56e4d53f..f383a3ae 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -618,6 +618,16 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "sazid",
+      "name": "Mohammed Sazid Al Rashid",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/2370167?v=4",
+      "profile": "https://sazid.github.io",
+      "contributions": [
+        "content",
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 21bfb2d4777429c87d8d3b5fbf0ce66006dcd034 Mon Sep 17 00:00:00 2001
From: Caleb Webber <caleb@codingthemsoftly.com>
Date: Thu, 5 Nov 2020 03:59:25 -0500
Subject: [PATCH 006/126] fix(installation): Update the MinRustVersion

closes #577df

Co-authored-by: Caleb Webber <seeplusplus@users.noreply.github.com>
---
 install.ps1 | 2 +-
 install.sh  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/install.ps1 b/install.ps1
index f7472ad1..32167f06 100644
--- a/install.ps1
+++ b/install.ps1
@@ -53,7 +53,7 @@ function vercomp($v1, $v2) {
 }
 
 $rustVersion = $(rustc --version).Split(" ")[1]
-$minRustVersion = "1.31"
+$minRustVersion = "1.39"
 if ((vercomp $rustVersion $minRustVersion) -eq 2) {
     Write-Host "WARNING: Rust version is too old: $rustVersion - needs at least $minRustVersion"
     Write-Host "Please update Rust with 'rustup update'"
diff --git a/install.sh b/install.sh
index a19c280a..e986e741 100755
--- a/install.sh
+++ b/install.sh
@@ -87,7 +87,7 @@ function vercomp() {
 }
 
 RustVersion=$(rustc --version | cut -d " " -f 2)
-MinRustVersion=1.31
+MinRustVersion=1.39
 vercomp $RustVersion $MinRustVersion
 if [ $? -eq 2 ]
 then

From 68e646f8aa04b4297fe205472334132cdf001bbc Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Thu, 5 Nov 2020 10:03:43 +0100
Subject: [PATCH 007/126] docs: add seeplusplus as a contributor

---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index f383a3ae..84b2365e 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -628,6 +628,15 @@
         "content",
         "code"
       ]
+    },
+    {
+      "login": "seeplusplus",
+      "name": "Caleb Webber",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/17479099?v=4",
+      "profile": "https://codingthemsoftly.com",
+      "contributions": [
+        "maintenance"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index 81962273..75a403f5 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-67-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-68-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️ [![Build status](https://badge.buildkite.com/7af93d81dc522c67a1ec8e33ff5705861b1cb36360b774807f.svg)](https://buildkite.com/mokou/rustlings)
@@ -232,6 +232,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/AnnikaCodes"><img src="https://avatars3.githubusercontent.com/u/56906084?v=4" width="100px;" alt=""/><br /><sub><b>Annika</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAnnikaCodes" title="Reviewed Pull Requests">👀</a></td>
     <td align="center"><a href="https://darnuria.eu"><img src="https://avatars1.githubusercontent.com/u/2827553?v=4" width="100px;" alt=""/><br /><sub><b>Axel Viala</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=darnuria" title="Code">💻</a></td>
     <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
+    <td align="center"><a href="https://codingthemsoftly.com"><img src="https://avatars1.githubusercontent.com/u/17479099?v=4" width="100px;" alt=""/><br /><sub><b>Caleb Webber</b></sub></a><br /><a href="#maintenance-seeplusplus" title="Maintenance">🚧</a></td>
   </tr>
 </table>
 

From d61b4e5a13b44d72d004082f523fa1b6b24c1aca Mon Sep 17 00:00:00 2001
From: Caleb Webber <caleb@codingthemsoftly.com>
Date: Thu, 5 Nov 2020 19:29:16 -0500
Subject: [PATCH 008/126] fix: log error output when inotify limit is exceeded

closes #472
---
 src/main.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index b5814bfb..d0299e33 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -119,7 +119,12 @@ fn main() {
         verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
     }
 
-    if matches.subcommand_matches("watch").is_some() && watch(&exercises, verbose).is_ok() {
+    if matches.subcommand_matches("watch").is_some() {
+        if let Err(e) = watch(&exercises, verbose) {
+            println!("Error: Could not watch your progess. Error message was {:?}.", e);
+            println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
+            std::process::exit(1);
+        }
         println!(
             "{emoji} All exercises completed! {emoji}",
             emoji = Emoji("🎉", "★")

From 197d3a3d8961b2465579218a6749b2b2cefa8ddd Mon Sep 17 00:00:00 2001
From: JP <jose@palako.com>
Date: Sat, 7 Nov 2020 13:54:14 +0100
Subject: [PATCH 009/126] fix(iterators2): Update description (#578)

grammar fix in the description
---
 exercises/standard_library_types/iterators2.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs
index 837725f0..84d14ae6 100644
--- a/exercises/standard_library_types/iterators2.rs
+++ b/exercises/standard_library_types/iterators2.rs
@@ -1,5 +1,5 @@
 // iterators2.rs
-// In this module, you'll learn some of unique advantages that iterators can offer.
+// In this module, you'll learn some of the unique advantages that iterators can offer.
 // Step 1. Complete the `capitalize_first` function to pass the first two cases.
 // Step 2. Apply the `capitalize_first` function to a vector of strings.
 //         Ensure that it returns a vector of strings as well.

From 95ccd92616ae79ba287cce221101e0bbe4f68cdc Mon Sep 17 00:00:00 2001
From: fiplox <56274824+fiplox@users.noreply.github.com>
Date: Sat, 7 Nov 2020 14:01:39 +0100
Subject: [PATCH 010/126] feat(try_from_into): Add tests (#571)

Co-authored-by: Volodymyr Patuta <6977238-fiplox@users.noreply.gitlab.com>
---
 exercises/conversions/try_from_into.rs | 93 ++++++++++++++++----------
 1 file changed, 56 insertions(+), 37 deletions(-)

diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index b830c166..cd14daf7 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -4,7 +4,7 @@
 // You can read more about it at https://doc.rust-lang.org/std/convert/trait.TryFrom.html
 use std::convert::{TryFrom, TryInto};
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 struct Color {
     red: u8,
     green: u8,
@@ -25,22 +25,19 @@ struct Color {
 // Tuple implementation
 impl TryFrom<(i16, i16, i16)> for Color {
     type Error = String;
-    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
-    }
+    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
 }
 
 // Array implementation
 impl TryFrom<[i16; 3]> for Color {
     type Error = String;
-    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
-    }
+    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
 }
 
 // Slice implementation
 impl TryFrom<&[i16]> for Color {
     type Error = String;
-    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
-    }
+    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
 }
 
 fn main() {
@@ -66,71 +63,93 @@ mod tests {
     use super::*;
 
     #[test]
-    #[should_panic]
     fn test_tuple_out_of_range_positive() {
-        let _ = Color::try_from((256, 1000, 10000)).unwrap();
+        assert!(Color::try_from((256, 1000, 10000)).is_err());
     }
     #[test]
-    #[should_panic]
     fn test_tuple_out_of_range_negative() {
-        let _ = Color::try_from((-1, -10, -256)).unwrap();
+        assert!(Color::try_from((-1, -10, -256)).is_err());
+    }
+    #[test]
+    fn test_tuple_sum() {
+        assert!(Color::try_from((-1, 255, 255)).is_err());
     }
     #[test]
     fn test_tuple_correct() {
-        let c: Color = (183, 65, 14).try_into().unwrap();
-        assert_eq!(c.red, 183);
-        assert_eq!(c.green, 65);
-        assert_eq!(c.blue, 14);
+        let c: Result<Color, String> = (183, 65, 14).try_into();
+        assert_eq!(
+            c,
+            Ok(Color {
+                red: 183,
+                green: 65,
+                blue: 14
+            })
+        );
     }
-
     #[test]
-    #[should_panic]
     fn test_array_out_of_range_positive() {
-        let _: Color = [1000, 10000, 256].try_into().unwrap();
+        let c: Color = [1000, 10000, 256].try_into();
+        assert!(c.is_err());
     }
     #[test]
-    #[should_panic]
     fn test_array_out_of_range_negative() {
-        let _: Color = [-10, -256, -1].try_into().unwrap();
+        let c: Color = [-10, -256, -1].try_into();
+        assert!(c.is_err());
     }
     #[test]
+    fn test_array_sum() {
+        let c: Color = [-1, 255, 255].try_into();
+        assert!(c.is_err());
+    }
+    #[test]
+    #[test]
     fn test_array_correct() {
-        let c: Color = [183, 65, 14].try_into().unwrap();
-        assert_eq!(c.red, 183);
-        assert_eq!(c.green, 65);
-        assert_eq!(c.blue, 14);
+        let c: Result<Color, String> = [183, 65, 14].try_into();
+        assert_eq!(
+            c,
+            Ok(Color {
+                red: 183,
+                green: 65,
+                blue: 14
+            })
+        );
     }
-
     #[test]
-    #[should_panic]
     fn test_slice_out_of_range_positive() {
         let arr = [10000, 256, 1000];
-        let _ = Color::try_from(&arr[..]).unwrap();
+        assert!(Color::try_from(&arr[..]).is_err());
     }
     #[test]
-    #[should_panic]
     fn test_slice_out_of_range_negative() {
         let arr = [-256, -1, -10];
-        let _ = Color::try_from(&arr[..]).unwrap();
+        assert!(Color::try_from(&arr[..]).is_err());
+    }
+    #[test]
+    fn test_slice_sum() {
+        let arr = [-1, 255, 255];
+        assert!(Color::try_from(&arr[..]).is_err());
     }
     #[test]
     fn test_slice_correct() {
         let v = vec![183, 65, 14];
-        let c = Color::try_from(&v[..]).unwrap();
-        assert_eq!(c.red, 183);
-        assert_eq!(c.green, 65);
-        assert_eq!(c.blue, 14);
+        let c: Result<Color, String> = Color::try_from(&v[..]);
+        assert_eq!(
+            c,
+            Ok(Color {
+                red: 183,
+                green: 65,
+                blue: 14
+            })
+        );
     }
     #[test]
-    #[should_panic]
     fn test_slice_excess_length() {
         let v = vec![0, 0, 0, 0];
-        let _ = Color::try_from(&v[..]).unwrap();
+        assert!(Color::try_from(&v[..]).is_err());
     }
     #[test]
-    #[should_panic]
     fn test_slice_insufficient_length() {
         let v = vec![0, 0];
-        let _ = Color::try_from(&v[..]).unwrap();
+        assert!(Color::try_from(&v[..]).is_err());
     }
 }

From 964b2a331de2c98c1038fd859ac7e7c0e956236a Mon Sep 17 00:00:00 2001
From: mokou <mokou@posteo.de>
Date: Sat, 7 Nov 2020 14:21:10 +0100
Subject: [PATCH 011/126] release: 4.2.0

---
 CHANGELOG.md | 21 +++++++++++++++++++++
 Cargo.lock   |  2 +-
 Cargo.toml   |  2 +-
 README.md    |  2 +-
 4 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d156aa6..d58d4e6b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,24 @@
+<a name="4.2.0"></a>
+## 4.2.0 (2020-11-07)
+
+#### Features
+
+*   Add HashMap exercises ([633c00cf](https://github.com/rust-lang/rustlings/commit/633c00cf8071e1e82959a3010452a32f34f29fc9))
+*   Add Vec exercises ([0c12fa31](https://github.com/rust-lang/rustlings/commit/0c12fa31c57c03c6287458a0a8aca7afd057baf6))
+* **primitive_types6:**  Add a test (#548) ([2b1fb2b7](https://github.com/rust-lang/rustlings/commit/2b1fb2b739bf9ad8d6b7b12af25fee173011bfc4))
+* **try_from_into:**  Add tests (#571) ([95ccd926](https://github.com/rust-lang/rustlings/commit/95ccd92616ae79ba287cce221101e0bbe4f68cdc))
+
+#### Bug Fixes
+
+*   log error output when inotify limit is exceeded ([d61b4e5a](https://github.com/rust-lang/rustlings/commit/d61b4e5a13b44d72d004082f523fa1b6b24c1aca))
+*   more unique temp_file ([5643ef05](https://github.com/rust-lang/rustlings/commit/5643ef05bc81e4a840e9456f4406a769abbe1392))
+* **installation:**  Update the MinRustVersion ([21bfb2d4](https://github.com/rust-lang/rustlings/commit/21bfb2d4777429c87d8d3b5fbf0ce66006dcd034))
+* **iterators2:**  Update description (#578) ([197d3a3d](https://github.com/rust-lang/rustlings/commit/197d3a3d8961b2465579218a6749b2b2cefa8ddd))
+* **primitive_types6:**
+  *  remove 'unused doc comment' warning ([472d8592](https://github.com/rust-lang/rustlings/commit/472d8592d65c8275332a20dfc269e7ac0d41bc88))
+  *  missing comma in test ([4fb230da](https://github.com/rust-lang/rustlings/commit/4fb230daf1251444fcf29e085cee222a91f8a37e))
+* **quiz3:**  Second test is for odd numbers, not even. (#553) ([18e0bfef](https://github.com/rust-lang/rustlings/commit/18e0bfef1de53071e353ba1ec5837002ff7290e6))
+
 <a name="4.1.0"></a>
 ## 4.1.0 (2020-10-05)
 
diff --git a/Cargo.lock b/Cargo.lock
index cdc1af35..9f90e0a1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -592,7 +592,7 @@ dependencies = [
 
 [[package]]
 name = "rustlings"
-version = "4.1.0"
+version = "4.2.0"
 dependencies = [
  "assert_cmd 0.11.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/Cargo.toml b/Cargo.toml
index 68142845..ebce25eb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rustlings"
-version = "4.1.0"
+version = "4.2.0"
 authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com>"]
 edition = "2018"
 
diff --git a/README.md b/README.md
index 75a403f5..59ee6328 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@ Basically: Clone the repository, checkout to the latest tag, run `cargo install`
 ```bash
 git clone https://github.com/rust-lang/rustlings
 cd rustlings
-git checkout tags/4.1.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
+git checkout tags/4.2.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
 cargo install --force --path .
 ```
 

From 9334783da31d821cc59174fbe8320df95828926c Mon Sep 17 00:00:00 2001
From: Brock <58987761+13r0ck@users.noreply.github.com>
Date: Sun, 8 Nov 2020 02:31:45 -0700
Subject: [PATCH 012/126] fix(structs1): Adjust wording (#573)

Co-authored-by: fmoko <mokou@posteo.de>
---
 info.toml | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/info.toml b/info.toml
index c52702f7..cc12c99d 100644
--- a/info.toml
+++ b/info.toml
@@ -225,12 +225,13 @@ name = "structs1"
 path = "exercises/structs/structs1.rs"
 mode = "test"
 hint = """
-Rust has more than one type of struct. Both variants are used to package related data together.
-On the one hand, there are normal, or classic, structs. These are named collections of related data stored in fields.
-The other variant is tuple structs. Basically just named tuples.
-In this exercise you need to implement one of each kind.
+Rust has more than one type of struct. Three actually, all variants are used to package related data together.
+There are normal (or classic) structs. These are named collections of related data stored in fields.
+Tuple structs are basically just named tuples.
+Finally, Unit structs. These don't have and fields and are useful for generics.
 
-Read more about structs in The Book: https://doc.rust-lang.org/stable/book/ch05-00-structs.html"""
+In this exercise you need to complete and implement one of each kind.
+Read more about structs in The Book: https://doc.rust-lang.org/book/ch05-01-defining-structs.html"""
 
 [[exercises]]
 name = "structs2"

From 96347df9df294f01153b29d9ad4ba361f665c755 Mon Sep 17 00:00:00 2001
From: JP <jose@palako.com>
Date: Sun, 8 Nov 2020 19:30:40 +0100
Subject: [PATCH 013/126] fix(try_from_into): Update description (#584)

Description update
---
 exercises/conversions/try_from_into.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index cd14daf7..38ce2db7 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -15,12 +15,12 @@ struct Color {
 
 // Your task is to complete this implementation
 // and return an Ok result of inner type Color.
-// You need create implementation for a tuple of three integer,
-// an array of three integer and slice of integer.
+// You need to create an implementation for a tuple of three integers,
+// an array of three integers and a slice of integers.
 //
-// Note, that implementation for tuple and array will be checked at compile-time,
-// but slice implementation need check slice length!
-// Also note, that chunk of correct rgb color must be integer in range 0..=255.
+// Note that the implementation for tuple and array will be checked at compile time,
+// but the slice implementation needs to check the slice length!
+// Also note that correct RGB color values must be integers in the 0..=255 range.
 
 // Tuple implementation
 impl TryFrom<(i16, i16, i16)> for Color {

From 838f9f30083d0b23fd67503dcf0fbeca498e6647 Mon Sep 17 00:00:00 2001
From: Caleb Webber <caleb@codingthemsoftly.com>
Date: Tue, 10 Nov 2020 12:36:19 -0500
Subject: [PATCH 014/126] feat: add "rustlings list" command

---
 src/main.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index d0299e33..d04ad8f6 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -54,6 +54,11 @@ fn main() {
                 .about("Returns a hint for the current exercise")
                 .arg(Arg::with_name("name").required(true).index(1)),
         )
+        .subcommand(
+            SubCommand::with_name("list")
+                .alias("l")
+                .about("Lists the exercises available in rustlings")
+        )
         .get_matches();
 
     if matches.subcommand_name().is_none() {
@@ -88,6 +93,9 @@ fn main() {
     let exercises = toml::from_str::<ExerciseList>(toml_str).unwrap().exercises;
     let verbose = matches.is_present("nocapture");
 
+    if matches.subcommand_matches("list").is_some() {
+        exercises.iter().for_each(|e| println!("{}", e.name));
+    }
     if let Some(ref matches) = matches.subcommand_matches("run") {
         let name = matches.value_of("name").unwrap();
 

From fa9f522b7f043d7ef73a39f003a9272dfe72c4f4 Mon Sep 17 00:00:00 2001
From: Brock <58987761+13r0ck@users.noreply.github.com>
Date: Wed, 11 Nov 2020 15:06:14 -0700
Subject: [PATCH 015/126] feat: Crab? (#586)

Crab?
---
 src/main.rs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index d04ad8f6..35f8df4d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -138,6 +138,26 @@ fn main() {
             emoji = Emoji("🎉", "★")
         );
         println!();
+        println!("+----------------------------------------------------+");     
+        println!("|          You made it to the Fe-nish line!          |");       
+        println!("+--------------------------  ------------------------+");       
+        println!("                          \\/                         ");
+        println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");        
+        println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");        
+        println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");        
+        println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");        
+        println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");        
+        println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");      
+        println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");    
+        println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");  
+        println!("           ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒         ");
+        println!("             ▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒           ");
+        println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");  
+        println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");    
+        println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");    
+        println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");    
+        println!("           ▒▒  ▒▒                      ▒▒  ▒▒         ");
+        println!();
         println!("We hope you enjoyed learning about the various aspects of Rust!");
         println!("If you noticed any issues, please don't hesitate to report them to our repo.");
         println!("You can also contribute your own exercises to help the greater community!");

From 4f4cfcf3c36c8718c7c170c9c3a6935e6ef0618c Mon Sep 17 00:00:00 2001
From: Wei Hu <wei.hu@send2china.co.uk>
Date: Wed, 11 Nov 2020 21:02:00 -0800
Subject: [PATCH 016/126] fix(try_from_into): type error

---
 exercises/conversions/try_from_into.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index 38ce2db7..897b364e 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -88,17 +88,17 @@ mod tests {
     }
     #[test]
     fn test_array_out_of_range_positive() {
-        let c: Color = [1000, 10000, 256].try_into();
+        let c: Result<Color, String> = [1000, 10000, 256].try_into();
         assert!(c.is_err());
     }
     #[test]
     fn test_array_out_of_range_negative() {
-        let c: Color = [-10, -256, -1].try_into();
+        let c: Result<Color, String> = [-10, -256, -1].try_into();
         assert!(c.is_err());
     }
     #[test]
     fn test_array_sum() {
-        let c: Color = [-1, 255, 255].try_into();
+        let c: Result<Color, String> = [-1, 255, 255].try_into();
         assert!(c.is_err());
     }
     #[test]

From d6d57bfbb8190edef5fcd7ecb4a20c8944ca87b1 Mon Sep 17 00:00:00 2001
From: fmoko <mokou@posteo.de>
Date: Thu, 12 Nov 2020 09:50:39 +0100
Subject: [PATCH 017/126] docs: Remove buildkite badge from README

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 59ee6328..fd45d945 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 [![All Contributors](https://img.shields.io/badge/all_contributors-68-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
-# rustlings 🦀❤️ [![Build status](https://badge.buildkite.com/7af93d81dc522c67a1ec8e33ff5705861b1cb36360b774807f.svg)](https://buildkite.com/mokou/rustlings)
+# rustlings 🦀❤️
 
 Greetings and welcome to `rustlings`. This project contains small exercises to get you used to reading and writing Rust code. This includes reading and responding to compiler messages!
 

From af7ad27f89d3e981076705cd7dd36ee0e6dcaaa6 Mon Sep 17 00:00:00 2001
From: fmoko <mokou@posteo.de>
Date: Thu, 12 Nov 2020 09:50:55 +0100
Subject: [PATCH 018/126] chore: Remove buildkite build file

---
 buildkite.yml | 5 -----
 1 file changed, 5 deletions(-)
 delete mode 100644 buildkite.yml

diff --git a/buildkite.yml b/buildkite.yml
deleted file mode 100644
index 91a0753c..00000000
--- a/buildkite.yml
+++ /dev/null
@@ -1,5 +0,0 @@
-steps:
-  - label: "Test with stable"
-    command: rustup run stable cargo test
-  - label: "Test with beta"
-    command: rustup run beta cargo test

From 9b6c629397b24b944f484f5b2bbd8144266b5695 Mon Sep 17 00:00:00 2001
From: Jacob Tinkhauser <75188781+tinkhauser@users.noreply.github.com>
Date: Sun, 29 Nov 2020 01:35:14 +0000
Subject: [PATCH 019/126] fix(vec1): Have test compare every element in a and v

The previous test would stop comparing elements in array a and vec v upon reaching the last element of either. This resulted in the test passing even if v did not contain all the elements in a. This change to the test fixes that bug and should only pass if all the elements in a and v are present and equal.
---
 exercises/collections/vec1.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/collections/vec1.rs b/exercises/collections/vec1.rs
index ac3d9f1a..f6bc837c 100644
--- a/exercises/collections/vec1.rs
+++ b/exercises/collections/vec1.rs
@@ -20,6 +20,6 @@ mod tests {
     #[test]
     fn test_array_and_vec_similarity() {
         let (a, v) = array_and_vec();
-        assert!(a.iter().zip(v.iter()).all(|(x, y)| x == y));
+        assert_eq!(a, v[..]);
     }
 }

From 04f1d079aa42a2f49af694bc92c67d731d31a53f Mon Sep 17 00:00:00 2001
From: Christos Kontas <xakon@yahoo.com>
Date: Thu, 3 Dec 2020 17:48:30 +0100
Subject: [PATCH 020/126] feat(try_from_into): remove duplicate annotation

---
 exercises/conversions/try_from_into.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index 897b364e..e405c3f4 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -102,7 +102,6 @@ mod tests {
         assert!(c.is_err());
     }
     #[test]
-    #[test]
     fn test_array_correct() {
         let c: Result<Color, String> = [183, 65, 14].try_into();
         assert_eq!(

From 033bf1198fc8bfce1b570e49da7cde010aa552e3 Mon Sep 17 00:00:00 2001
From: JuliaCao <y.cao@berkeley.edu>
Date: Mon, 7 Dec 2020 06:37:19 -0800
Subject: [PATCH 021/126] feat: match exercise order to book chapters (#541)

Added exercise to book chapter mapping table to exercise README
---
 exercises/README.md |  23 ++
 info.toml           | 634 ++++++++++++++++++++------------------------
 2 files changed, 304 insertions(+), 353 deletions(-)
 create mode 100644 exercises/README.md

diff --git a/exercises/README.md b/exercises/README.md
new file mode 100644
index 00000000..725edd7b
--- /dev/null
+++ b/exercises/README.md
@@ -0,0 +1,23 @@
+# Exercise to Book Chapter mapping
+
+| Exercise               | Book Chapter |
+|------------------------|--------------|
+| variables              | §3.1          |
+| functions              | §3.3          |
+| if                     | §3.5          |
+| move_semantics         | §4.1          |
+| primitive_types        | §4.3          |
+| structs                | §5.1          |
+| enums                  | §6            |
+| modules                | §7.2          |
+| strings                | §8.2          |
+| error_handling         | §9            |
+| generics               | §10           |
+| option                 | §10.1         |
+| traits                 | §10.2         |
+| tests                  | §11.1         |
+| standard_library_types | §13.2         |
+| threads                | §16.1         |
+| macros                 | §19.6         |
+| clippy                 | n/a           |
+| conversions            | n/a           |
diff --git a/info.toml b/info.toml
index cc12c99d..1b2eec21 100644
--- a/info.toml
+++ b/info.toml
@@ -71,31 +71,6 @@ Read more about constants under 'Differences Between Variables and Constants' in
 https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html#differences-between-variables-and-constants
 """
 
-# IF
-
-[[exercises]]
-name = "if1"
-path = "exercises/if/if1.rs"
-mode = "test"
-hint = """
-It's possible to do this in one line if you would like!
-Some similar examples from other languages:
-- In C(++) this would be: `a > b ? a : b`
-- In Python this would be:  `a if a > b else b`
-Remember in Rust that:
-- the `if` condition does not need to be surrounded by parentheses
-- `if`/`else` conditionals are expressions
-- Each condition is followed by a `{}` block."""
-
-[[exercises]]
-name = "if2"
-path = "exercises/if/if2.rs"
-mode = "test"
-hint = """
-For that first compiler error, it's important in Rust that each conditional
-block return the same type! To get the tests passing, you will need a couple
-conditions checking different input values."""
-
 # FUNCTIONS
 
 [[exercises]]
@@ -146,6 +121,31 @@ They are not the same. There are two solutions:
 1. Add a `return` ahead of `num * num;`
 2. remove `;`, make it to be `num * num`"""
 
+# IF
+
+[[exercises]]
+name = "if1"
+path = "exercises/if/if1.rs"
+mode = "test"
+hint = """
+It's possible to do this in one line if you would like!
+Some similar examples from other languages:
+- In C(++) this would be: `a > b ? a : b`
+- In Python this would be:  `a if a > b else b`
+Remember in Rust that:
+- the `if` condition does not need to be surrounded by parentheses
+- `if`/`else` conditionals are expressions
+- Each condition is followed by a `{}` block."""
+
+[[exercises]]
+name = "if2"
+path = "exercises/if/if2.rs"
+mode = "test"
+hint = """
+For that first compiler error, it's important in Rust that each conditional
+block return the same type! To get the tests passing, you will need a couple
+conditions checking different input values."""
+
 # TEST 1
 
 [[exercises]]
@@ -154,6 +154,62 @@ path = "exercises/quiz1.rs"
 mode = "test"
 hint = "No hints this time ;)"
 
+# MOVE SEMANTICS
+
+[[exercises]]
+name = "move_semantics1"
+path = "exercises/move_semantics/move_semantics1.rs"
+mode = "compile"
+hint = """
+So you've got the "cannot borrow immutable local variable `vec1` as mutable" error on line 13,
+right? The fix for this is going to be adding one keyword, and the addition is NOT on line 13
+where the error is."""
+
+[[exercises]]
+name = "move_semantics2"
+path = "exercises/move_semantics/move_semantics2.rs"
+mode = "compile"
+hint = """
+So `vec0` is being *moved* into the function `fill_vec` when we call it on
+line 10, which means it gets dropped at the end of `fill_vec`, which means we
+can't use `vec0` again on line 13 (or anywhere else in `main` after the
+`fill_vec` call for that matter). We could fix this in a few ways, try them
+all!
+1. Make another, separate version of the data that's in `vec0` and pass that
+   to `fill_vec` instead.
+2. Make `fill_vec` borrow its argument instead of taking ownership of it,
+   and then copy the data within the function in order to return an owned
+   `Vec<i32>`
+3. Make `fill_vec` *mutably* borrow its argument (which will need to be
+   mutable), modify it directly, then not return anything. Then you can get rid
+   of `vec1` entirely -- note that this will change what gets printed by the
+   first `println!`"""
+
+[[exercises]]
+name = "move_semantics3"
+path = "exercises/move_semantics/move_semantics3.rs"
+mode = "compile"
+hint = """
+The difference between this one and the previous ones is that the first line
+of `fn fill_vec` that had `let mut vec = vec;` is no longer there. You can,
+instead of adding that line back, add `mut` in one place that will change
+an existing binding to be a mutable binding instead of an immutable one :)"""
+
+[[exercises]]
+name = "move_semantics4"
+path = "exercises/move_semantics/move_semantics4.rs"
+mode = "compile"
+hint = """
+Stop reading whenever you feel like you have enough direction :) Or try
+doing one step and then fixing the compiler errors that result!
+So the end goal is to:
+   - get rid of the first line in main that creates the new vector
+   - so then `vec0` doesn't exist, so we can't pass it to `fill_vec`
+   - we don't want to pass anything to `fill_vec`, so its signature should
+     reflect that it does not take any arguments
+   - since we're not creating a new vec in `main` anymore, we need to create
+     a new vec in `fill_vec`, similarly to the way we did in `main`"""
+
 # PRIMITIVE TYPES
 
 [[exercises]]
@@ -255,6 +311,51 @@ For calculate_transport_fees: Bigger is more expensive usually, we don't have si
 
 Have a look in The Book, to find out more about method implementations: https://doc.rust-lang.org/book/ch05-03-method-syntax.html"""
 
+# ENUMS
+
+[[exercises]]
+name = "enums1"
+path = "exercises/enums/enums1.rs"
+mode = "compile"
+hint = """
+Hint: The declaration of the enumeration type has not been defined yet."""
+
+[[exercises]]
+name = "enums2"
+path = "exercises/enums/enums2.rs"
+mode = "compile"
+hint = """
+Hint: you can create enumerations that have different variants with different types
+such as no data, anonymous structs, a single string, tuples, ...etc"""
+
+[[exercises]]
+name = "enums3"
+path = "exercises/enums/enums3.rs"
+mode = "test"
+hint = "No hints this time ;)"
+
+# MODULES
+
+[[exercises]]
+name = "modules1"
+path = "exercises/modules/modules1.rs"
+mode = "compile"
+hint = """
+Everything is private in Rust by default-- but there's a keyword we can use
+to make something public! The compiler error should point to the thing that
+needs to be public."""
+
+[[exercises]]
+name = "modules2"
+path = "exercises/modules/modules2.rs"
+mode = "compile"
+hint = """
+The delicious_snacks module is trying to present an external
+interface (the `fruit` and `veggie` constants) that is different than
+its internal structure (the `fruits` and `veggies` modules and
+associated constants). It's almost there except for one keyword missing for
+each constant."""
+
 # STRINGS
 
 [[exercises]]
@@ -286,248 +387,6 @@ path = "exercises/quiz2.rs"
 mode = "compile"
 hint = "No hints this time ;)"
 
-# ENUMS
-
-[[exercises]]
-name = "enums1"
-path = "exercises/enums/enums1.rs"
-mode = "compile"
-hint = """
-Hint: The declaration of the enumeration type has not been defined yet."""
-
-[[exercises]]
-name = "enums2"
-path = "exercises/enums/enums2.rs"
-mode = "compile"
-hint = """
-Hint: you can create enumerations that have different variants with different types
-such as no data, anonymous structs, a single string, tuples, ...etc"""
-
-[[exercises]]
-name = "enums3"
-path = "exercises/enums/enums3.rs"
-mode = "test"
-hint = "No hints this time ;)"
-
-# TESTS
-
-[[exercises]]
-name = "tests1"
-path = "exercises/tests/tests1.rs"
-mode = "test"
-hint = """
-You don't even need to write any code to test -- you can just test values and run that, even
-though you wouldn't do that in real life :) `assert!` is a macro that needs an argument.
-Depending on the value of the argument, `assert!` will do nothing (in which case the test will
-pass) or `assert!` will panic (in which case the test will fail). So try giving different values
-to `assert!` and see which ones compile, which ones pass, and which ones fail :)"""
-
-[[exercises]]
-name = "tests2"
-path = "exercises/tests/tests2.rs"
-mode = "test"
-hint = """
-Like the previous exercise, you don't need to write any code to get this test to compile and
-run. `assert_eq!` is a macro that takes two arguments and compares them. Try giving it two
-values that are equal! Try giving it two arguments that are different! Try giving it two values
-that are of different types! Try switching which argument comes first and which comes second!"""
-
-[[exercises]]
-name = "tests3"
-path = "exercises/tests/tests3.rs"
-mode = "test"
-hint = """
-You can call a function right where you're passing arguments to `assert!` -- so you could do
-something like `assert!(having_fun())`. If you want to check that you indeed get false, you
-can negate the result of what you're doing using `!`, like `assert!(!having_fun())`."""
-
-# TEST 3
-
-[[exercises]]
-name = "quiz3"
-path = "exercises/quiz3.rs"
-mode = "test"
-hint = "No hints this time ;)"
-
-# MODULES
-
-[[exercises]]
-name = "modules1"
-path = "exercises/modules/modules1.rs"
-mode = "compile"
-hint = """
-Everything is private in Rust by default-- but there's a keyword we can use
-to make something public! The compiler error should point to the thing that
-needs to be public."""
-
-[[exercises]]
-name = "modules2"
-path = "exercises/modules/modules2.rs"
-mode = "compile"
-hint = """
-The delicious_snacks module is trying to present an external
-interface (the `fruit` and `veggie` constants) that is different than
-its internal structure (the `fruits` and `veggies` modules and
-associated constants). It's almost there except for one keyword missing for
-each constant."""
-
-# COLLECTIONS
-
-[[exercises]]
-name = "collections1"
-path = "exercises/collections/vec1.rs"
-mode = "test"
-hint = """
-In Rust, there are two ways to define a Vector.
-
-1. One way is to use the `Vec::new()` function to create a new vector
-  and fill it with the `push()` method.
-
-2. The second way, which is simpler is to use the `vec![]` macro and
-  define your elements inside the square brackets.
-
-Check this chapter: https://doc.rust-lang.org/stable/book/ch08-01-vectors.html
-of the Rust book to learn more.
-"""
-
-[[exercises]]
-name = "collections2"
-path = "exercises/collections/vec2.rs"
-mode = "test"
-hint = """
-Hint 1: `i` is each element from the Vec as they are being iterated.
-  Can you try multiplying this?
-
-Hint 2: Check the suggestion from the compiler error ;)
-"""
-
-[[exercises]]
-name = "collections3"
-path = "exercises/collections/hashmap1.rs"
-mode = "test"
-hint = """
-Hint 1: Take a look at the return type of the function to figure out
-  the type for the `basket`.
-
-Hint 2: Number of fruits should be at least 5. And you have to put
-  at least three different types of fruits.
-"""
-
-[[exercises]]
-name = "collections4"
-path = "exercises/collections/hashmap2.rs"
-mode = "test"
-hint = """
-Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this.
-
-Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value
-"""
-
-# MACROS
-
-[[exercises]]
-name = "macros1"
-path = "exercises/macros/macros1.rs"
-mode = "compile"
-hint = """
-When you call a macro, you need to add something special compared to a
-regular function call. If you're stuck, take a look at what's inside
-`my_macro`."""
-
-[[exercises]]
-name = "macros2"
-path = "exercises/macros/macros2.rs"
-mode = "compile"
-hint = """
-Macros don't quite play by the same rules as the rest of Rust, in terms of
-what's available where.
-
-Unlike other things in Rust, the order of "where you define a macro" versus
-"where you use it" actually matters."""
-
-[[exercises]]
-name = "macros3"
-path = "exercises/macros/macros3.rs"
-mode = "compile"
-hint = """
-In order to use a macro outside of its module, you need to do something
-special to the module to lift the macro out into its parent.
-
-The same trick also works on "extern crate" statements for crates that have
-exported macros, if you've seen any of those around."""
-
-[[exercises]]
-name = "macros4"
-path = "exercises/macros/macros4.rs"
-mode = "compile"
-hint = """
-You only need to add a single character to make this compile.
-The way macros are written, it wants to see something between each
-"macro arm", so it can separate them."""
-# TEST 4
-
-[[exercises]]
-name = "quiz4"
-path = "exercises/quiz4.rs"
-mode = "test"
-hint = "No hints this time ;)"
-
-# MOVE SEMANTICS
-
-[[exercises]]
-name = "move_semantics1"
-path = "exercises/move_semantics/move_semantics1.rs"
-mode = "compile"
-hint = """
-So you've got the "cannot borrow immutable local variable `vec1` as mutable" error on line 13,
-right? The fix for this is going to be adding one keyword, and the addition is NOT on line 13
-where the error is."""
-
-[[exercises]]
-name = "move_semantics2"
-path = "exercises/move_semantics/move_semantics2.rs"
-mode = "compile"
-hint = """
-So `vec0` is being *moved* into the function `fill_vec` when we call it on
-line 10, which means it gets dropped at the end of `fill_vec`, which means we
-can't use `vec0` again on line 13 (or anywhere else in `main` after the
-`fill_vec` call for that matter). We could fix this in a few ways, try them
-all!
-1. Make another, separate version of the data that's in `vec0` and pass that
-   to `fill_vec` instead.
-2. Make `fill_vec` borrow its argument instead of taking ownership of it,
-   and then copy the data within the function in order to return an owned
-   `Vec<i32>`
-3. Make `fill_vec` *mutably* borrow its argument (which will need to be
-   mutable), modify it directly, then not return anything. Then you can get rid
-   of `vec1` entirely -- note that this will change what gets printed by the
-   first `println!`"""
-
-[[exercises]]
-name = "move_semantics3"
-path = "exercises/move_semantics/move_semantics3.rs"
-mode = "compile"
-hint = """
-The difference between this one and the previous ones is that the first line
-of `fn fill_vec` that had `let mut vec = vec;` is no longer there. You can,
-instead of adding that line back, add `mut` in one place that will change
-an existing binding to be a mutable binding instead of an immutable one :)"""
-
-[[exercises]]
-name = "move_semantics4"
-path = "exercises/move_semantics/move_semantics4.rs"
-mode = "compile"
-hint = """
-Stop reading whenever you feel like you have enough direction :) Or try
-doing one step and then fixing the compiler errors that result!
-So the end goal is to:
-   - get rid of the first line in main that creates the new vector
-   - so then `vec0` doesn't exist, so we can't pass it to `fill_vec`
-   - we don't want to pass anything to `fill_vec`, so its signature should
-     reflect that it does not take any arguments
-   - since we're not creating a new vec in `main` anymore, we need to create
-     a new vec in `fill_vec`, similarly to the way we did in `main`"""
-
 # ERROR HANDLING
 
 [[exercises]]
@@ -607,6 +466,40 @@ get a warning if you don't handle a `Result` that you get in your
 function. Read more about that in the `std::result` module docs:
 https://doc.rust-lang.org/std/result/#results-must-be-used"""
 
+# Generics
+
+[[exercises]]
+name = "generics1"
+path = "exercises/generics/generics1.rs"
+mode = "compile"
+hint = """
+Vectors in rust make use of generics to create dynamically sized arrays of any type.
+You need to tell the compiler what type we are pushing onto this vector."""
+
+[[exercises]]
+name = "generics2"
+path = "exercises/generics/generics2.rs"
+mode = "test"
+hint = """
+Currently we are wrapping only values of type 'u32'.
+Maybe we could update the explicit references to this data type somehow?
+
+If you are still stuck https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-method-definitions
+"""
+
+[[exercises]]
+name = "generics3"
+path = "exercises/generics/generics3.rs"
+mode = "test"
+hint = """
+To find the best solution to this challenge you're going to need to think back to your
+knowledge of traits, specifically Trait Bound Syntax -  you may also need this: "use std::fmt::Display;"
+
+This is definitely harder than the last two exercises! You need to think about not only making the
+ReportCard struct generic, but also the correct property - you will need to change the implementation
+of the struct slightly too...you can do it!
+"""
+
 # OPTIONS / RESULTS
 
 [[exercises]]
@@ -649,21 +542,67 @@ hint = """
 It should be doing some checking, returning an `Err` result if those checks fail, and only
 returning an `Ok` result if those checks determine that everything is... okay :)"""
 
-#  CLIPPY
+# TRAITS
 
 [[exercises]]
-name = "clippy1"
-path = "exercises/clippy/clippy1.rs"
-mode = "clippy"
+name = "traits1"
+path = "exercises/traits/traits1.rs"
+mode = "test"
 hint = """
-Floating point calculations are usually imprecise, so asking if two values are exactly equal is asking for trouble"""
+A discussion about Traits in Rust can be found at:
+https://doc.rust-lang.org/book/ch10-02-traits.html
+"""
 
 [[exercises]]
-name = "clippy2"
-path = "exercises/clippy/clippy2.rs"
-mode = "clippy"
+name = "traits2"
+path = "exercises/traits/traits2.rs"
+mode = "test"
 hint = """
-`for` loops over Option values are more clearly expressed as an `if let`"""
+Notice how the trait takes ownership of 'self',and returns `Self'.
+Try mutating the incoming string vector.
+
+Vectors provide suitable methods for adding an element at the end. See
+the documentation at: https://doc.rust-lang.org/std/vec/struct.Vec.html"""
+
+# TESTS
+
+[[exercises]]
+name = "tests1"
+path = "exercises/tests/tests1.rs"
+mode = "test"
+hint = """
+You don't even need to write any code to test -- you can just test values and run that, even
+though you wouldn't do that in real life :) `assert!` is a macro that needs an argument.
+Depending on the value of the argument, `assert!` will do nothing (in which case the test will
+pass) or `assert!` will panic (in which case the test will fail). So try giving different values
+to `assert!` and see which ones compile, which ones pass, and which ones fail :)"""
+
+[[exercises]]
+name = "tests2"
+path = "exercises/tests/tests2.rs"
+mode = "test"
+hint = """
+Like the previous exercise, you don't need to write any code to get this test to compile and
+run. `assert_eq!` is a macro that takes two arguments and compares them. Try giving it two
+values that are equal! Try giving it two arguments that are different! Try giving it two values
+that are of different types! Try switching which argument comes first and which comes second!"""
+
+[[exercises]]
+name = "tests3"
+path = "exercises/tests/tests3.rs"
+mode = "test"
+hint = """
+You can call a function right where you're passing arguments to `assert!` -- so you could do
+something like `assert!(having_fun())`. If you want to check that you indeed get false, you
+can negate the result of what you're doing using `!`, like `assert!(!having_fun())`."""
+
+# TEST 3
+
+[[exercises]]
+name = "quiz3"
+path = "exercises/quiz3.rs"
+mode = "test"
+hint = "No hints this time ;)"
 
 # STANDARD LIBRARY TYPES
 
@@ -697,27 +636,6 @@ inside the loop but still in the main thread.
 `child_numbers` should be a clone of the Arc of the numbers instead of a
 thread-local copy of the numbers."""
 
-[[exercises]]
-name = "iterators1"
-path = "exercises/standard_library_types/iterators1.rs"
-mode = "compile"
-hint = """
-Step 1:
-We need to apply something to the collection `my_fav_fruits` before we start to go through
-it. What could that be? Take a look at the struct definition for a vector for inspiration:
-https://doc.rust-lang.org/std/vec/struct.Vec.html.
-
-
-Step 2 & step 2.1:
-Very similar to the lines above and below. You've got this!
-
-
-Step 3:
-An iterator goes through all elements in a collection, but what if we've run out of
-elements? What should we expect here? If you're stuck, take a look at 
-https://doc.rust-lang.org/std/iter/trait.Iterator.html for some ideas.
-"""
-
 [[exercises]]
 name = "iterators2"
 path = "exercises/standard_library_types/iterators2.rs"
@@ -761,62 +679,6 @@ a mutable variable. Or, you might write code utilizing recursion
 and a match clause. In Rust you can take another functional
 approach, computing the factorial elegantly with ranges and iterators."""
 
-# TRAITS
-
-[[exercises]]
-name = "traits1"
-path = "exercises/traits/traits1.rs"
-mode = "test"
-hint = """
-A discussion about Traits in Rust can be found at:
-https://doc.rust-lang.org/book/ch10-02-traits.html
-"""
-
-[[exercises]]
-name = "traits2"
-path = "exercises/traits/traits2.rs"
-mode = "test"
-hint = """
-Notice how the trait takes ownership of 'self',and returns `Self'.
-Try mutating the incoming string vector.
-
-Vectors provide suitable methods for adding an element at the end. See
-the documentation at: https://doc.rust-lang.org/std/vec/struct.Vec.html"""
-
-# Generics
-
-[[exercises]]
-name = "generics1"
-path = "exercises/generics/generics1.rs"
-mode = "compile"
-hint = """
-Vectors in rust make use of generics to create dynamically sized arrays of any type.
-You need to tell the compiler what type we are pushing onto this vector."""
-
-[[exercises]]
-name = "generics2"
-path = "exercises/generics/generics2.rs"
-mode = "test"
-hint = """
-Currently we are wrapping only values of type 'u32'.
-Maybe we could update the explicit references to this data type somehow?
-
-If you are still stuck https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-method-definitions
-"""
-
-[[exercises]]
-name = "generics3"
-path = "exercises/generics/generics3.rs"
-mode = "test"
-hint = """
-To find the best solution to this challenge you're going to need to think back to your
-knowledge of traits, specifically Trait Bound Syntax -  you may also need this: "use std::fmt::Display;"
-
-This is definitely harder than the last two exercises! You need to think about not only making the
-ReportCard struct generic, but also the correct property - you will need to change the implementation
-of the struct slightly too...you can do it!
-"""
-
 # THREADS
 
 [[exercises]]
@@ -856,6 +718,72 @@ If you've learned from the sample solutions, I encourage you to come
 back to this exercise and try it again in a few days to reinforce
 what you've learned :)"""
 
+# MACROS
+
+[[exercises]]
+name = "macros1"
+path = "exercises/macros/macros1.rs"
+mode = "compile"
+hint = """
+When you call a macro, you need to add something special compared to a
+regular function call. If you're stuck, take a look at what's inside
+`my_macro`."""
+
+[[exercises]]
+name = "macros2"
+path = "exercises/macros/macros2.rs"
+mode = "compile"
+hint = """
+Macros don't quite play by the same rules as the rest of Rust, in terms of
+what's available where.
+
+Unlike other things in Rust, the order of "where you define a macro" versus
+"where you use it" actually matters."""
+
+[[exercises]]
+name = "macros3"
+path = "exercises/macros/macros3.rs"
+mode = "compile"
+hint = """
+In order to use a macro outside of its module, you need to do something
+special to the module to lift the macro out into its parent.
+
+The same trick also works on "extern crate" statements for crates that have
+exported macros, if you've seen any of those around."""
+
+[[exercises]]
+name = "macros4"
+path = "exercises/macros/macros4.rs"
+mode = "compile"
+hint = """
+You only need to add a single character to make this compile.
+The way macros are written, it wants to see something between each
+"macro arm", so it can separate them."""
+
+# TEST 4
+
+[[exercises]]
+name = "quiz4"
+path = "exercises/quiz4.rs"
+mode = "test"
+hint = "No hints this time ;)"
+
+#  CLIPPY
+
+[[exercises]]
+name = "clippy1"
+path = "exercises/clippy/clippy1.rs"
+mode = "clippy"
+hint = """
+Floating point calculations are usually imprecise, so asking if two values are exactly equal is asking for trouble"""
+
+[[exercises]]
+name = "clippy2"
+path = "exercises/clippy/clippy2.rs"
+mode = "clippy"
+hint = """
+`for` loops over Option values are more clearly expressed as an `if let`"""
+
 # TYPE CONVERSIONS
 
 [[exercises]]

From 30644c9a062b825c0ea89435dc59f0cad86b110e Mon Sep 17 00:00:00 2001
From: Peter N <spacey-github.com@ssr.com>
Date: Tue, 8 Dec 2020 06:08:25 -0300
Subject: [PATCH 022/126] fix: gives a bit more context to magic number

---
 exercises/threads/threads1.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/exercises/threads/threads1.rs b/exercises/threads/threads1.rs
index 1785e8ce..b475b4a1 100644
--- a/exercises/threads/threads1.rs
+++ b/exercises/threads/threads1.rs
@@ -1,7 +1,8 @@
 // threads1.rs
 // Make this compile! Execute `rustlings hint threads1` for hints :)
 // The idea is the thread spawned on line 21 is completing jobs while the main thread is
-// monitoring progress until 10 jobs are completed. If you see 6 lines
+// monitoring progress until 10 jobs are completed. Because of the difference between the
+// spawned threads' sleep time, and the waiting threads sleep time, when you see 6 lines
 // of "waiting..." and the program ends without timing out when running,
 // you've got it :)
 

From 26110da7cadc4ab7614730c2d0b1e514a2763d3d Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 8 Dec 2020 10:12:57 +0100
Subject: [PATCH 023/126] docs: add pcn as a contributor

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 84b2365e..388bf5ff 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -637,6 +637,15 @@
       "contributions": [
         "maintenance"
       ]
+    },
+    {
+      "login": "pcn",
+      "name": "Peter N",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/1056756?v=4",
+      "profile": "https://github.com/pcn",
+      "contributions": [
+        "maintenance"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index fd45d945..49ceb2c9 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-68-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-69-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -233,6 +233,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://darnuria.eu"><img src="https://avatars1.githubusercontent.com/u/2827553?v=4" width="100px;" alt=""/><br /><sub><b>Axel Viala</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=darnuria" title="Code">💻</a></td>
     <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
     <td align="center"><a href="https://codingthemsoftly.com"><img src="https://avatars1.githubusercontent.com/u/17479099?v=4" width="100px;" alt=""/><br /><sub><b>Caleb Webber</b></sub></a><br /><a href="#maintenance-seeplusplus" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/pcn"><img src="https://avatars2.githubusercontent.com/u/1056756?v=4" width="100px;" alt=""/><br /><sub><b>Peter N</b></sub></a><br /><a href="#maintenance-pcn" title="Maintenance">🚧</a></td>
   </tr>
 </table>
 

From 90cfb6ff28377531bfc34acb70547bdb13374f6b Mon Sep 17 00:00:00 2001
From: JuliaCao <y.cao@berkeley.edu>
Date: Sat, 12 Dec 2020 10:21:23 -0800
Subject: [PATCH 024/126] fix: added missing exercises to info.toml

---
 exercises/README.md |  1 +
 info.toml           | 63 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/exercises/README.md b/exercises/README.md
index 725edd7b..0c715247 100644
--- a/exercises/README.md
+++ b/exercises/README.md
@@ -10,6 +10,7 @@
 | structs                | §5.1          |
 | enums                  | §6            |
 | modules                | §7.2          |
+| collections            | §8.1          |
 | strings                | §8.2          |
 | error_handling         | §9            |
 | generics               | §10           |
diff --git a/info.toml b/info.toml
index 1b2eec21..f1fc3981 100644
--- a/info.toml
+++ b/info.toml
@@ -356,6 +356,52 @@ its internal structure (the `fruits` and `veggies` modules and
 associated constants). It's almost there except for one keyword missing for
 each constant."""
 
+# COLLECTIONS
+
+[[exercises]]
+name = "collections1"
+path = "exercises/collections/vec1.rs"
+mode = "test"
+hint = """
+In Rust, there are two ways to define a Vector.
+1. One way is to use the `Vec::new()` function to create a new vector
+  and fill it with the `push()` method.
+2. The second way, which is simpler is to use the `vec![]` macro and
+  define your elements inside the square brackets.
+Check this chapter: https://doc.rust-lang.org/stable/book/ch08-01-vectors.html
+of the Rust book to learn more.
+"""
+
+[[exercises]]
+name = "collections2"
+path = "exercises/collections/vec2.rs"
+mode = "test"
+hint = """
+Hint 1: `i` is each element from the Vec as they are being iterated.
+  Can you try multiplying this?
+Hint 2: Check the suggestion from the compiler error ;)
+"""
+
+[[exercises]]
+name = "collections3"
+path = "exercises/collections/hashmap1.rs"
+mode = "test"
+hint = """
+Hint 1: Take a look at the return type of the function to figure out
+  the type for the `basket`.
+Hint 2: Number of fruits should be at least 5. And you have to put
+  at least three different types of fruits.
+"""
+
+[[exercises]]
+name = "collections4"
+path = "exercises/collections/hashmap2.rs"
+mode = "test"
+hint = """
+Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this.
+Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value
+"""
+
 # STRINGS
 
 [[exercises]]
@@ -636,6 +682,23 @@ inside the loop but still in the main thread.
 `child_numbers` should be a clone of the Arc of the numbers instead of a
 thread-local copy of the numbers."""
 
+[[exercises]]
+name = "iterators1"
+path = "exercises/standard_library_types/iterators1.rs"
+mode = "compile"
+hint = """
+Step 1:
+We need to apply something to the collection `my_fav_fruits` before we start to go through
+it. What could that be? Take a look at the struct definition for a vector for inspiration:
+https://doc.rust-lang.org/std/vec/struct.Vec.html.
+Step 2 & step 2.1:
+Very similar to the lines above and below. You've got this!
+Step 3:
+An iterator goes through all elements in a collection, but what if we've run out of
+elements? What should we expect here? If you're stuck, take a look at 
+https://doc.rust-lang.org/std/iter/trait.Iterator.html for some ideas.
+"""
+
 [[exercises]]
 name = "iterators2"
 path = "exercises/standard_library_types/iterators2.rs"

From bcf14cf677adb3a38a3ac3ca53f3c69f61153025 Mon Sep 17 00:00:00 2001
From: seancad <47405611+seancad@users.noreply.github.com>
Date: Tue, 15 Dec 2020 00:32:46 -0700
Subject: [PATCH 025/126] fix: update structs README

---
 exercises/structs/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/structs/README.md b/exercises/structs/README.md
index afbc72c8..d2d7dc24 100644
--- a/exercises/structs/README.md
+++ b/exercises/structs/README.md
@@ -4,4 +4,4 @@ Rust has three struct types: a classic c struct, a tuple struct, and a unit stru
 
 #### Book Sections
 
-- [Structures](https://doc.rust-lang.org/rust-by-example/custom_types/structs.html)
+- [Structures](https://doc.rust-lang.org/book/ch05-01-defining-structs.html)

From 4ac70a99aea688a629e5d7ef99bb8686fa7f6301 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 15 Dec 2020 08:33:47 +0100
Subject: [PATCH 026/126] docs: add seancad as a contributor

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 388bf5ff..1549aa45 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -646,6 +646,15 @@
       "contributions": [
         "maintenance"
       ]
+    },
+    {
+      "login": "seancad",
+      "name": "seancad",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/47405611?v=4",
+      "profile": "https://github.com/seancad",
+      "contributions": [
+        "maintenance"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index 49ceb2c9..7a2c94c6 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-69-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-70-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -234,6 +234,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
     <td align="center"><a href="https://codingthemsoftly.com"><img src="https://avatars1.githubusercontent.com/u/17479099?v=4" width="100px;" alt=""/><br /><sub><b>Caleb Webber</b></sub></a><br /><a href="#maintenance-seeplusplus" title="Maintenance">🚧</a></td>
     <td align="center"><a href="https://github.com/pcn"><img src="https://avatars2.githubusercontent.com/u/1056756?v=4" width="100px;" alt=""/><br /><sub><b>Peter N</b></sub></a><br /><a href="#maintenance-pcn" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/seancad"><img src="https://avatars1.githubusercontent.com/u/47405611?v=4" width="100px;" alt=""/><br /><sub><b>seancad</b></sub></a><br /><a href="#maintenance-seancad" title="Maintenance">🚧</a></td>
   </tr>
 </table>
 

From 0ef95947cc30482e63a7045be6cc2fb6f6dcb4cc Mon Sep 17 00:00:00 2001
From: Axel Viala <axel.viala@darnuria.eu>
Date: Sun, 27 Dec 2020 12:36:38 +0100
Subject: [PATCH 027/126] fix(functions2): Change signature to trigger precise
 error message: (#605)

Now trigger this error:
```
error: expected type, found `)`
  --> exercises/functions/functions2.rs:10:16
   |
10 | fn call_me(num:) {
   |                ^ expected type

```
---
 exercises/functions/functions2.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/functions/functions2.rs b/exercises/functions/functions2.rs
index 108ba38b..5721a172 100644
--- a/exercises/functions/functions2.rs
+++ b/exercises/functions/functions2.rs
@@ -7,7 +7,7 @@ fn main() {
     call_me(3);
 }
 
-fn call_me(num) {
+fn call_me(num:) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

From 28020d0c54e795c465f59cb92954599de8834549 Mon Sep 17 00:00:00 2001
From: mokou <mokou@posteo.de>
Date: Tue, 29 Dec 2020 11:23:08 +0100
Subject: [PATCH 028/126] docs: Add note on uninstalling to README

---
 README.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/README.md b/README.md
index 7a2c94c6..9512ac5c 100644
--- a/README.md
+++ b/README.md
@@ -118,6 +118,24 @@ cargo uninstall rustlings
 rm -r rustlings/ # or on Windows: rmdir /s rustlings
 ```
 
+## Uninstalling Rustlings
+
+If you want to remove Rustlings from your system, there's two steps. First, you'll need to remove the exercises folder that the install script created
+for you:
+
+``` bash
+rm -rf rustlings # or your custom folder name, if you chose and or renamed it
+```
+
+Second, since Rustlings got installed via `cargo install`, it's only reasonable to assume that you can also remove it using Cargo, and
+exactly that is the case. Run `cargo uninstall` to remove the `rustlings` binary:
+
+``` bash
+cargo uninstall rustlings
+```
+
+Now you should be done!
+
 ## Completion
 
 Rustlings isn't done; there are a couple of sections that are very experimental and don't have proper documentation. These include:

From 44d39112ff122b29c9793fe52e605df1612c6490 Mon Sep 17 00:00:00 2001
From: mokou <mokou@posteo.de>
Date: Tue, 29 Dec 2020 11:34:52 +0100
Subject: [PATCH 029/126] feat: Rewrite default out text

This has been in place for a long time now, before we had an install
script, so it ended up repeating a bunch of the same things that the
install script does automatically. I rewrote it so that it gives more
helpful information about how you're supposed to do Rustlings.
Hopefully this will reduce the number of "I started Rustlings and it
gave me an error" issues (no offense to anyone who opened one of those,
it was pretty unclear that it _wasn't_ an error).
---
 default_out.txt | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/default_out.txt b/default_out.txt
index 05267591..44b7734c 100644
--- a/default_out.txt
+++ b/default_out.txt
@@ -1,19 +1,25 @@
 Thanks for installing Rustlings!
 
-Is this your first time?
+Is this your first time? Don't worry, Rustlings was made for beginners! We are
+going to teach you a lot of things about Rust, but before we can get
+started, here's a couple of notes about how Rustlings operates:
 
-Let's make sure you're up to speed:
-- You have Rust installed, preferably via `rustup`
-- You have `~/.cargo/bin` added to your PATH variable
-- You have cloned this repository (https://github.com/rust-lang/rustlings)
-- You have installed Rust language support for your editor
-- You have locally installed the `rustlings` command by running an
-  installation script or manually executing:
+1. The central concept behind Rustlings is that you solve exercises. These
+   exercises usually have some sort of syntax error in them, which will cause
+   them to fail compliation or testing. Sometimes there's a logic error instead
+   of a syntax error. No matter what error, it's your job to find it and fix it!
+   You'll know when you fixed it because then, the exercise will compile and
+   Rustlings will be able to move on to the next exercise.
+2. If you run Rustlings in watch mode (which we recommend), it'll automatically
+   start with the first exercise. Don't get confused by an error message popping
+   up as soon as you run Rustlings! This is part of the exercise that you're
+   supposed to solve, so open the exercise file in an editor and start your
+   detective work!
+3. If you're stuck on an exercise, there is a helpful hint you can view by typing
+   'hint' (in watch mode), or running `rustlings hint myexercise`.
+4. If an exercise doesn't make sense to you, feel free to open an issue on GitHub!
+   (https://github.com/rust-lang/rustlings/issues/new). We look at every issue,
+   and sometimes, other learners do too so you can help each other out!
 
-cargo install --force --path .
-
-If you've done all of this (or even most of it), congrats! You're ready
-to start working with Rust.
-
-To get started, run `rustlings watch` in order to get the first exercise.
-Make sure to have your editor open!
+Got all that? Great! To get started, run `rustlings watch` in order to get the first
+exercise. Make sure to have your editor open!

From a303d508cf0c5bc20bb50bd388b2545bf80672ac Mon Sep 17 00:00:00 2001
From: mokou <mokou@posteo.de>
Date: Tue, 29 Dec 2020 11:39:26 +0100
Subject: [PATCH 030/126] release: 4.3.0

---
 CHANGELOG.md |  23 ++
 Cargo.lock   | 590 +++++++++++++++++++++++++--------------------------
 Cargo.toml   |   2 +-
 README.md    |   2 +-
 src/main.rs  |   2 +-
 5 files changed, 320 insertions(+), 299 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d58d4e6b..3988826e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,26 @@
+<a name="4.3.0"></a>
+## 4.3.0 (2020-12-29)
+
+#### Features
+
+*   Rewrite default out text ([44d39112](https://github.com/rust-lang/rustlings/commit/44d39112ff122b29c9793fe52e605df1612c6490))
+*   match exercise order to book chapters (#541) ([033bf119](https://github.com/rust-lang/rustlings/commit/033bf1198fc8bfce1b570e49da7cde010aa552e3))
+*   Crab? (#586) ([fa9f522b](https://github.com/rust-lang/rustlings/commit/fa9f522b7f043d7ef73a39f003a9272dfe72c4f4))
+*   add "rustlings list" command ([838f9f30](https://github.com/rust-lang/rustlings/commit/838f9f30083d0b23fd67503dcf0fbeca498e6647))
+* **try_from_into:**  remove duplicate annotation ([04f1d079](https://github.com/rust-lang/rustlings/commit/04f1d079aa42a2f49af694bc92c67d731d31a53f))
+
+#### Bug Fixes
+
+*   update structs README ([bcf14cf6](https://github.com/rust-lang/rustlings/commit/bcf14cf677adb3a38a3ac3ca53f3c69f61153025))
+*   added missing exercises to info.toml ([90cfb6ff](https://github.com/rust-lang/rustlings/commit/90cfb6ff28377531bfc34acb70547bdb13374f6b))
+*   gives a bit more context to magic number ([30644c9a](https://github.com/rust-lang/rustlings/commit/30644c9a062b825c0ea89435dc59f0cad86b110e))
+* **functions2:**  Change signature to trigger precise error message: (#605) ([0ef95947](https://github.com/rust-lang/rustlings/commit/0ef95947cc30482e63a7045be6cc2fb6f6dcb4cc))
+* **structs1:**  Adjust wording (#573) ([9334783d](https://github.com/rust-lang/rustlings/commit/9334783da31d821cc59174fbe8320df95828926c))
+* **try_from_into:**
+  *  type error ([4f4cfcf3](https://github.com/rust-lang/rustlings/commit/4f4cfcf3c36c8718c7c170c9c3a6935e6ef0618c))
+  *  Update description (#584) ([96347df9](https://github.com/rust-lang/rustlings/commit/96347df9df294f01153b29d9ad4ba361f665c755))
+* **vec1:**  Have test compare every element in a and v ([9b6c6293](https://github.com/rust-lang/rustlings/commit/9b6c629397b24b944f484f5b2bbd8144266b5695))
+
 <a name="4.2.0"></a>
 ## 4.2.0 (2020-11-07)
 
diff --git a/Cargo.lock b/Cargo.lock
index 9f90e0a1..4a4313e7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,917 +4,915 @@
 name = "aho-corasick"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6f484ae0c99fec2e858eb6134949117399f222608d84cadb3f58c1f97c2364c"
 dependencies = [
- "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr",
 ]
 
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 dependencies = [
- "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8",
 ]
 
 [[package]]
 name = "assert_cmd"
 version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dc477793bd82ec39799b6f6b3df64938532fdf2ab0d49ef817eac65856a5a1e"
 dependencies = [
- "escargot 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "predicates 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "predicates-core 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "predicates-tree 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "escargot",
+ "predicates",
+ "predicates-core",
+ "predicates-tree",
 ]
 
 [[package]]
 name = "atty"
 version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 dependencies = [
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-"checksum winapi-util 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7168bab6e1daee33b4557efd0e95d5ca70a03706d39fa5f3fe7a236f584b03c9"
-"checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
-"checksum ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d59cefebd0c892fa2dd6de581e937301d8552cb44489cdff035c6187cb63fa5e"
diff --git a/Cargo.toml b/Cargo.toml
index ebce25eb..a0564c37 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rustlings"
-version = "4.2.0"
+version = "4.3.0"
 authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com>"]
 edition = "2018"
 
diff --git a/README.md b/README.md
index 9512ac5c..a5371043 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@ Basically: Clone the repository, checkout to the latest tag, run `cargo install`
 ```bash
 git clone https://github.com/rust-lang/rustlings
 cd rustlings
-git checkout tags/4.2.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
+git checkout tags/4.3.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
 cargo install --force --path .
 ```
 
diff --git a/src/main.rs b/src/main.rs
index 35f8df4d..bf35e4fb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -25,7 +25,7 @@ mod verify;
 fn main() {
     let matches = App::new("rustlings")
         .version(crate_version!())
-        .author("Olivia Hugger, Carol Nichols")
+        .author("Marisa, Carol Nichols")
         .about("Rustlings is a collection of small exercises to get you used to writing and reading Rust code")
         .arg(
             Arg::with_name("nocapture")

From 644c49f1e04cbb24e95872b3a52b07d692ae3bc8 Mon Sep 17 00:00:00 2001
From: xehpuk <xehpuk.dev@gmail.com>
Date: Wed, 30 Dec 2020 22:56:04 +0100
Subject: [PATCH 031/126] fix: typo in default out text

---
 default_out.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/default_out.txt b/default_out.txt
index 44b7734c..b90d1e3a 100644
--- a/default_out.txt
+++ b/default_out.txt
@@ -6,7 +6,7 @@ started, here's a couple of notes about how Rustlings operates:
 
 1. The central concept behind Rustlings is that you solve exercises. These
    exercises usually have some sort of syntax error in them, which will cause
-   them to fail compliation or testing. Sometimes there's a logic error instead
+   them to fail compilation or testing. Sometimes there's a logic error instead
    of a syntax error. No matter what error, it's your job to find it and fix it!
    You'll know when you fixed it because then, the exercise will compile and
    Rustlings will be able to move on to the next exercise.

From ff6cba7205fc9b1a5cbb10dcf4f7887b153a4930 Mon Sep 17 00:00:00 2001
From: RoelofWobben <75732370+RoelofWobben@users.noreply.github.com>
Date: Sun, 27 Dec 2020 10:49:55 +0100
Subject: [PATCH 032/126] Update README.md

---
 README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/README.md b/README.md
index a5371043..16f8c3d8 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,8 @@ Start-BitsTransfer -Source https://git.io/rustlings-win -Destination $env:TMP/in
 
 To install Rustlings. Same as on MacOS/Linux, you will have access to the `rustlings` command after it.
 
+When you get a permission denied message then you have to exclude the directory where you placed the rustlings in your virus-scanner
+
 ## Browser:
 
 [Run on Repl.it](https://repl.it/github/rust-lang/rustlings)

From e9b42bbc2a20df848950375a5baafc0620017a9c Mon Sep 17 00:00:00 2001
From: Will Hayworth <whayworth@gmail.com>
Date: Sun, 3 Jan 2021 03:42:39 -0800
Subject: [PATCH 033/126] docs: mention flatten in the options2 hint

---
 info.toml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/info.toml b/info.toml
index ee4ab2f6..15cd3f3f 100644
--- a/info.toml
+++ b/info.toml
@@ -583,8 +583,7 @@ https://doc.rust-lang.org/rust-by-example/flow_control/while_let.html
 
 Remember that Options can be stacked in if let and while let.
 For example: Some(Some(variable)) = variable2
-
-
+Also see Option::flatten
 """
 
 [[exercises]]

From c355ac6593e94e09459dea93a11371f132913123 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 4 Jan 2021 13:12:10 +0000
Subject: [PATCH 034/126] docs: update README.md [skip ci]

---
 README.md | 146 +++++++++++++++++++++++++++---------------------------
 1 file changed, 74 insertions(+), 72 deletions(-)

diff --git a/README.md b/README.md
index 16f8c3d8..b67793d4 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-70-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-71-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -169,97 +169,99 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 <!-- markdownlint-disable -->
 <table>
   <tr>
-    <td align="center"><a href="http://carol-nichols.com"><img src="https://avatars2.githubusercontent.com/u/193874?v=4" width="100px;" alt=""/><br /><sub><b>Carol (Nichols &#124;&#124; Goulding)</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=carols10cents" title="Code">💻</a> <a href="#content-carols10cents" title="Content">🖋</a></td>
-    <td align="center"><a href="https://twitter.com/QuietMisdreavus"><img src="https://avatars2.githubusercontent.com/u/5217170?v=4" width="100px;" alt=""/><br /><sub><b>QuietMisdreavus</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=QuietMisdreavus" title="Code">💻</a> <a href="#content-QuietMisdreavus" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/robertlugg"><img src="https://avatars0.githubusercontent.com/u/6054540?v=4" width="100px;" alt=""/><br /><sub><b>Robert M Lugg</b></sub></a><br /><a href="#content-robertlugg" title="Content">🖋</a></td>
-    <td align="center"><a href="https://hynek.me/about/"><img src="https://avatars3.githubusercontent.com/u/41240?v=4" width="100px;" alt=""/><br /><sub><b>Hynek Schlawack</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=hynek" title="Code">💻</a></td>
-    <td align="center"><a href="https://spacekookie.de"><img src="https://avatars0.githubusercontent.com/u/7669898?v=4" width="100px;" alt=""/><br /><sub><b>Katharina Fey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=spacekookie" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/lukabavdaz"><img src="https://avatars0.githubusercontent.com/u/9624558?v=4" width="100px;" alt=""/><br /><sub><b>lukabavdaz</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lukabavdaz" title="Code">💻</a> <a href="#content-lukabavdaz" title="Content">🖋</a></td>
-    <td align="center"><a href="http://vestera.as"><img src="https://avatars2.githubusercontent.com/u/4187449?v=4" width="100px;" alt=""/><br /><sub><b>Erik Vesteraas</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=evestera" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/Delet0r"><img src="https://avatars1.githubusercontent.com/u/23195618?v=4" width="100px;" alt=""/><br /><sub><b>delet0r</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Delet0r" title="Code">💻</a></td>
+    <td align="center"><a href="http://carol-nichols.com"><img src="https://avatars2.githubusercontent.com/u/193874?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Carol (Nichols &#124;&#124; Goulding)</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=carols10cents" title="Code">💻</a> <a href="#content-carols10cents" title="Content">🖋</a></td>
+    <td align="center"><a href="https://twitter.com/QuietMisdreavus"><img src="https://avatars2.githubusercontent.com/u/5217170?v=4?s=100" width="100px;" alt=""/><br /><sub><b>QuietMisdreavus</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=QuietMisdreavus" title="Code">💻</a> <a href="#content-QuietMisdreavus" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/robertlugg"><img src="https://avatars0.githubusercontent.com/u/6054540?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Robert M Lugg</b></sub></a><br /><a href="#content-robertlugg" title="Content">🖋</a></td>
+    <td align="center"><a href="https://hynek.me/about/"><img src="https://avatars3.githubusercontent.com/u/41240?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Hynek Schlawack</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=hynek" title="Code">💻</a></td>
+    <td align="center"><a href="https://spacekookie.de"><img src="https://avatars0.githubusercontent.com/u/7669898?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Katharina Fey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=spacekookie" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/lukabavdaz"><img src="https://avatars0.githubusercontent.com/u/9624558?v=4?s=100" width="100px;" alt=""/><br /><sub><b>lukabavdaz</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lukabavdaz" title="Code">💻</a> <a href="#content-lukabavdaz" title="Content">🖋</a></td>
+    <td align="center"><a href="http://vestera.as"><img src="https://avatars2.githubusercontent.com/u/4187449?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Erik Vesteraas</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=evestera" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/Delet0r"><img src="https://avatars1.githubusercontent.com/u/23195618?v=4?s=100" width="100px;" alt=""/><br /><sub><b>delet0r</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Delet0r" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="http://phinary.ca"><img src="https://avatars1.githubusercontent.com/u/10522375?v=4" width="100px;" alt=""/><br /><sub><b>Shaun Bennett</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=shaunbennett" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/abagshaw"><img src="https://avatars2.githubusercontent.com/u/8594541?v=4" width="100px;" alt=""/><br /><sub><b>Andrew Bagshaw</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=abagshaw" title="Code">💻</a></td>
-    <td align="center"><a href="https://ai6ua.net/"><img src="https://avatars2.githubusercontent.com/u/175578?v=4" width="100px;" alt=""/><br /><sub><b>Kyle Isom</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=kisom" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/ColinPitrat"><img src="https://avatars3.githubusercontent.com/u/1541863?v=4" width="100px;" alt=""/><br /><sub><b>Colin Pitrat</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ColinPitrat" title="Code">💻</a></td>
-    <td align="center"><a href="https://zacanger.com"><img src="https://avatars3.githubusercontent.com/u/12520493?v=4" width="100px;" alt=""/><br /><sub><b>Zac Anger</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=zacanger" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/mgeier"><img src="https://avatars1.githubusercontent.com/u/705404?v=4" width="100px;" alt=""/><br /><sub><b>Matthias Geier</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=mgeier" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/cjpearce"><img src="https://avatars1.githubusercontent.com/u/3453268?v=4" width="100px;" alt=""/><br /><sub><b>Chris Pearce</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=cjpearce" title="Code">💻</a></td>
-    <td align="center"><a href="https://yvan-sraka.github.io"><img src="https://avatars2.githubusercontent.com/u/705213?v=4" width="100px;" alt=""/><br /><sub><b>Yvan Sraka</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=yvan-sraka" title="Code">💻</a></td>
+    <td align="center"><a href="http://phinary.ca"><img src="https://avatars1.githubusercontent.com/u/10522375?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Shaun Bennett</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=shaunbennett" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/abagshaw"><img src="https://avatars2.githubusercontent.com/u/8594541?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Andrew Bagshaw</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=abagshaw" title="Code">💻</a></td>
+    <td align="center"><a href="https://ai6ua.net/"><img src="https://avatars2.githubusercontent.com/u/175578?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Kyle Isom</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=kisom" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/ColinPitrat"><img src="https://avatars3.githubusercontent.com/u/1541863?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Colin Pitrat</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ColinPitrat" title="Code">💻</a></td>
+    <td align="center"><a href="https://zacanger.com"><img src="https://avatars3.githubusercontent.com/u/12520493?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Zac Anger</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=zacanger" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/mgeier"><img src="https://avatars1.githubusercontent.com/u/705404?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Matthias Geier</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=mgeier" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/cjpearce"><img src="https://avatars1.githubusercontent.com/u/3453268?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Chris Pearce</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=cjpearce" title="Code">💻</a></td>
+    <td align="center"><a href="https://yvan-sraka.github.io"><img src="https://avatars2.githubusercontent.com/u/705213?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Yvan Sraka</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=yvan-sraka" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/dendi239"><img src="https://avatars3.githubusercontent.com/u/16478650?v=4" width="100px;" alt=""/><br /><sub><b>Denys Smirnov</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=dendi239" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/eddyp"><img src="https://avatars2.githubusercontent.com/u/123772?v=4" width="100px;" alt=""/><br /><sub><b>eddyp</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=eddyp" title="Code">💻</a></td>
-    <td align="center"><a href="http://about.me/BrianKung"><img src="https://avatars1.githubusercontent.com/u/2836167?v=4" width="100px;" alt=""/><br /><sub><b>Brian Kung</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=briankung" title="Code">💻</a> <a href="#content-briankung" title="Content">🖋</a></td>
-    <td align="center"><a href="https://rcousineau.gitlab.io"><img src="https://avatars3.githubusercontent.com/u/281039?v=4" width="100px;" alt=""/><br /><sub><b>Russell</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=miller-time" title="Code">💻</a></td>
-    <td align="center"><a href="http://danwilhelm.com"><img src="https://avatars3.githubusercontent.com/u/6137185?v=4" width="100px;" alt=""/><br /><sub><b>Dan Wilhelm</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=danwilhelm" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/Jesse-Cameron"><img src="https://avatars3.githubusercontent.com/u/3723654?v=4" width="100px;" alt=""/><br /><sub><b>Jesse</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Jesse-Cameron" title="Code">💻</a> <a href="#content-Jesse-Cameron" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/MrFroop"><img src="https://avatars3.githubusercontent.com/u/196700?v=4" width="100px;" alt=""/><br /><sub><b>Fredrik Jambrén</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=MrFroop" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/petemcfarlane"><img src="https://avatars3.githubusercontent.com/u/3472717?v=4" width="100px;" alt=""/><br /><sub><b>Pete McFarlane</b></sub></a><br /><a href="#content-petemcfarlane" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/dendi239"><img src="https://avatars3.githubusercontent.com/u/16478650?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Denys Smirnov</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=dendi239" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/eddyp"><img src="https://avatars2.githubusercontent.com/u/123772?v=4?s=100" width="100px;" alt=""/><br /><sub><b>eddyp</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=eddyp" title="Code">💻</a></td>
+    <td align="center"><a href="http://about.me/BrianKung"><img src="https://avatars1.githubusercontent.com/u/2836167?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Brian Kung</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=briankung" title="Code">💻</a> <a href="#content-briankung" title="Content">🖋</a></td>
+    <td align="center"><a href="https://rcousineau.gitlab.io"><img src="https://avatars3.githubusercontent.com/u/281039?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Russell</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=miller-time" title="Code">💻</a></td>
+    <td align="center"><a href="http://danwilhelm.com"><img src="https://avatars3.githubusercontent.com/u/6137185?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Dan Wilhelm</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=danwilhelm" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/Jesse-Cameron"><img src="https://avatars3.githubusercontent.com/u/3723654?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jesse</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Jesse-Cameron" title="Code">💻</a> <a href="#content-Jesse-Cameron" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/MrFroop"><img src="https://avatars3.githubusercontent.com/u/196700?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Fredrik Jambrén</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=MrFroop" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/petemcfarlane"><img src="https://avatars3.githubusercontent.com/u/3472717?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pete McFarlane</b></sub></a><br /><a href="#content-petemcfarlane" title="Content">🖋</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/nkanderson"><img src="https://avatars0.githubusercontent.com/u/4128825?v=4" width="100px;" alt=""/><br /><sub><b>nkanderson</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=nkanderson" title="Code">💻</a> <a href="#content-nkanderson" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/ajaxm"><img src="https://avatars0.githubusercontent.com/u/13360138?v=4" width="100px;" alt=""/><br /><sub><b>Ajax M</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ajaxm" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://dylnuge.com"><img src="https://avatars2.githubusercontent.com/u/118624?v=4" width="100px;" alt=""/><br /><sub><b>Dylan Nugent</b></sub></a><br /><a href="#content-Dylnuge" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/vyaslav"><img src="https://avatars0.githubusercontent.com/u/1385427?v=4" width="100px;" alt=""/><br /><sub><b>vyaslav</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=vyaslav" title="Code">💻</a> <a href="#content-vyaslav" title="Content">🖋</a></td>
-    <td align="center"><a href="https://join.sfxd.org"><img src="https://avatars1.githubusercontent.com/u/17297466?v=4" width="100px;" alt=""/><br /><sub><b>George</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=gdoenlen" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/nyxtom"><img src="https://avatars2.githubusercontent.com/u/222763?v=4" width="100px;" alt=""/><br /><sub><b>Thomas Holloway</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=nyxtom" title="Code">💻</a> <a href="#content-nyxtom" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/workingjubilee"><img src="https://avatars1.githubusercontent.com/u/46493976?v=4" width="100px;" alt=""/><br /><sub><b>Jubilee</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=workingjubilee" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/WofWca"><img src="https://avatars1.githubusercontent.com/u/39462442?v=4" width="100px;" alt=""/><br /><sub><b>WofWca</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=WofWca" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/nkanderson"><img src="https://avatars0.githubusercontent.com/u/4128825?v=4?s=100" width="100px;" alt=""/><br /><sub><b>nkanderson</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=nkanderson" title="Code">💻</a> <a href="#content-nkanderson" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/ajaxm"><img src="https://avatars0.githubusercontent.com/u/13360138?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ajax M</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ajaxm" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://dylnuge.com"><img src="https://avatars2.githubusercontent.com/u/118624?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Dylan Nugent</b></sub></a><br /><a href="#content-Dylnuge" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/vyaslav"><img src="https://avatars0.githubusercontent.com/u/1385427?v=4?s=100" width="100px;" alt=""/><br /><sub><b>vyaslav</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=vyaslav" title="Code">💻</a> <a href="#content-vyaslav" title="Content">🖋</a></td>
+    <td align="center"><a href="https://join.sfxd.org"><img src="https://avatars1.githubusercontent.com/u/17297466?v=4?s=100" width="100px;" alt=""/><br /><sub><b>George</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=gdoenlen" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/nyxtom"><img src="https://avatars2.githubusercontent.com/u/222763?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Thomas Holloway</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=nyxtom" title="Code">💻</a> <a href="#content-nyxtom" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/workingjubilee"><img src="https://avatars1.githubusercontent.com/u/46493976?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jubilee</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=workingjubilee" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/WofWca"><img src="https://avatars1.githubusercontent.com/u/39462442?v=4?s=100" width="100px;" alt=""/><br /><sub><b>WofWca</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=WofWca" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/jrvidal"><img src="https://avatars0.githubusercontent.com/u/1636604?v=4" width="100px;" alt=""/><br /><sub><b>Roberto Vidal</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jrvidal" title="Code">💻</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jrvidal" title="Documentation">📖</a> <a href="#ideas-jrvidal" title="Ideas, Planning, & Feedback">🤔</a> <a href="#maintenance-jrvidal" title="Maintenance">🚧</a></td>
-    <td align="center"><a href="https://github.com/jensim"><img src="https://avatars0.githubusercontent.com/u/3663856?v=4" width="100px;" alt=""/><br /><sub><b>Jens</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jensim" title="Documentation">📖</a></td>
-    <td align="center"><a href="http://rahatah.me/d"><img src="https://avatars3.githubusercontent.com/u/3174006?v=4" width="100px;" alt=""/><br /><sub><b>Rahat Ahmed</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=rahatarmanahmed" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/AbdouSeck"><img src="https://avatars2.githubusercontent.com/u/6490055?v=4" width="100px;" alt=""/><br /><sub><b>Abdou Seck</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=AbdouSeck" title="Code">💻</a> <a href="#content-AbdouSeck" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAbdouSeck" title="Reviewed Pull Requests">👀</a></td>
-    <td align="center"><a href="https://codehearts.com"><img src="https://avatars0.githubusercontent.com/u/2885412?v=4" width="100px;" alt=""/><br /><sub><b>Katie</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=codehearts" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/Socratides"><img src="https://avatars3.githubusercontent.com/u/27732983?v=4" width="100px;" alt=""/><br /><sub><b>Socrates</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Socratides" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/gnodarse"><img src="https://avatars3.githubusercontent.com/u/46761795?v=4" width="100px;" alt=""/><br /><sub><b>gnodarse</b></sub></a><br /><a href="#content-gnodarse" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/harrisonmetz"><img src="https://avatars1.githubusercontent.com/u/7883408?v=4" width="100px;" alt=""/><br /><sub><b>Harrison Metzger</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=harrisonmetz" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/jrvidal"><img src="https://avatars0.githubusercontent.com/u/1636604?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Roberto Vidal</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jrvidal" title="Code">💻</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jrvidal" title="Documentation">📖</a> <a href="#ideas-jrvidal" title="Ideas, Planning, & Feedback">🤔</a> <a href="#maintenance-jrvidal" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/jensim"><img src="https://avatars0.githubusercontent.com/u/3663856?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jens</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jensim" title="Documentation">📖</a></td>
+    <td align="center"><a href="http://rahatah.me/d"><img src="https://avatars3.githubusercontent.com/u/3174006?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rahat Ahmed</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=rahatarmanahmed" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/AbdouSeck"><img src="https://avatars2.githubusercontent.com/u/6490055?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Abdou Seck</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=AbdouSeck" title="Code">💻</a> <a href="#content-AbdouSeck" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAbdouSeck" title="Reviewed Pull Requests">👀</a></td>
+    <td align="center"><a href="https://codehearts.com"><img src="https://avatars0.githubusercontent.com/u/2885412?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Katie</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=codehearts" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/Socratides"><img src="https://avatars3.githubusercontent.com/u/27732983?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Socrates</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Socratides" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/gnodarse"><img src="https://avatars3.githubusercontent.com/u/46761795?v=4?s=100" width="100px;" alt=""/><br /><sub><b>gnodarse</b></sub></a><br /><a href="#content-gnodarse" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/harrisonmetz"><img src="https://avatars1.githubusercontent.com/u/7883408?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Harrison Metzger</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=harrisonmetz" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/TorbenJ"><img src="https://avatars2.githubusercontent.com/u/9077102?v=4" width="100px;" alt=""/><br /><sub><b>Torben Jonas</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=TorbenJ" title="Code">💻</a> <a href="#content-TorbenJ" title="Content">🖋</a></td>
-    <td align="center"><a href="http://paulbissex.com/"><img src="https://avatars0.githubusercontent.com/u/641?v=4" width="100px;" alt=""/><br /><sub><b>Paul Bissex</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=pbx" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/sjmann"><img src="https://avatars0.githubusercontent.com/u/6589896?v=4" width="100px;" alt=""/><br /><sub><b>Steven Mann</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sjmann" title="Code">💻</a> <a href="#content-sjmann" title="Content">🖋</a></td>
-    <td align="center"><a href="https://smmdb.net/"><img src="https://avatars2.githubusercontent.com/u/5855071?v=4" width="100px;" alt=""/><br /><sub><b>Mario Reder</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Tarnadas" title="Code">💻</a> <a href="#content-Tarnadas" title="Content">🖋</a></td>
-    <td align="center"><a href="https://keybase.io/skim"><img src="https://avatars0.githubusercontent.com/u/47347?v=4" width="100px;" alt=""/><br /><sub><b>skim</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sl4m" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/sanjaykdragon"><img src="https://avatars1.githubusercontent.com/u/10261698?v=4" width="100px;" alt=""/><br /><sub><b>Sanjay K</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sanjaykdragon" title="Code">💻</a> <a href="#content-sanjaykdragon" title="Content">🖋</a></td>
-    <td align="center"><a href="http://www.rohanjain.in"><img src="https://avatars1.githubusercontent.com/u/343499?v=4" width="100px;" alt=""/><br /><sub><b>Rohan Jain</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=crodjer" title="Code">💻</a></td>
-    <td align="center"><a href="https://www.saidaspen.se"><img src="https://avatars1.githubusercontent.com/u/7727687?v=4" width="100px;" alt=""/><br /><sub><b>Said Aspen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=saidaspen" title="Code">💻</a> <a href="#content-saidaspen" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/TorbenJ"><img src="https://avatars2.githubusercontent.com/u/9077102?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Torben Jonas</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=TorbenJ" title="Code">💻</a> <a href="#content-TorbenJ" title="Content">🖋</a></td>
+    <td align="center"><a href="http://paulbissex.com/"><img src="https://avatars0.githubusercontent.com/u/641?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Paul Bissex</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=pbx" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/sjmann"><img src="https://avatars0.githubusercontent.com/u/6589896?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Steven Mann</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sjmann" title="Code">💻</a> <a href="#content-sjmann" title="Content">🖋</a></td>
+    <td align="center"><a href="https://smmdb.net/"><img src="https://avatars2.githubusercontent.com/u/5855071?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Mario Reder</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Tarnadas" title="Code">💻</a> <a href="#content-Tarnadas" title="Content">🖋</a></td>
+    <td align="center"><a href="https://keybase.io/skim"><img src="https://avatars0.githubusercontent.com/u/47347?v=4?s=100" width="100px;" alt=""/><br /><sub><b>skim</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sl4m" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/sanjaykdragon"><img src="https://avatars1.githubusercontent.com/u/10261698?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Sanjay K</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sanjaykdragon" title="Code">💻</a> <a href="#content-sanjaykdragon" title="Content">🖋</a></td>
+    <td align="center"><a href="http://www.rohanjain.in"><img src="https://avatars1.githubusercontent.com/u/343499?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rohan Jain</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=crodjer" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.saidaspen.se"><img src="https://avatars1.githubusercontent.com/u/7727687?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Said Aspen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=saidaspen" title="Code">💻</a> <a href="#content-saidaspen" title="Content">🖋</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/uce"><img src="https://avatars3.githubusercontent.com/u/1756620?v=4" width="100px;" alt=""/><br /><sub><b>Ufuk Celebi</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=uce" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/lebedevsergey"><img src="https://avatars2.githubusercontent.com/u/7325764?v=4" width="100px;" alt=""/><br /><sub><b>lebedevsergey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lebedevsergey" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/avrong"><img src="https://avatars2.githubusercontent.com/u/6342851?v=4" width="100px;" alt=""/><br /><sub><b>Aleksei Trifonov</b></sub></a><br /><a href="#content-avrong" title="Content">🖋</a></td>
-    <td align="center"><a href="https://drn.ie"><img src="https://avatars2.githubusercontent.com/u/411136?v=4" width="100px;" alt=""/><br /><sub><b>Darren Meehan</b></sub></a><br /><a href="#content-Darrenmeehan" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/jihchi"><img src="https://avatars1.githubusercontent.com/u/87983?v=4" width="100px;" alt=""/><br /><sub><b>Jihchi Lee</b></sub></a><br /><a href="#content-jihchi" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/bertonha"><img src="https://avatars3.githubusercontent.com/u/1225902?v=4" width="100px;" alt=""/><br /><sub><b>Christofer Bertonha</b></sub></a><br /><a href="#content-bertonha" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/apatniv"><img src="https://avatars2.githubusercontent.com/u/22565917?v=4" width="100px;" alt=""/><br /><sub><b>Vivek Bharath Akupatni</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=apatniv" title="Code">💻</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apatniv" title="Tests">⚠️</a></td>
-    <td align="center"><a href="https://github.com/DiD92"><img src="https://avatars3.githubusercontent.com/u/6002416?v=4" width="100px;" alt=""/><br /><sub><b>Dídac Sementé Fernández</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=DiD92" title="Code">💻</a> <a href="#content-DiD92" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/uce"><img src="https://avatars3.githubusercontent.com/u/1756620?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ufuk Celebi</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=uce" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/lebedevsergey"><img src="https://avatars2.githubusercontent.com/u/7325764?v=4?s=100" width="100px;" alt=""/><br /><sub><b>lebedevsergey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lebedevsergey" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/avrong"><img src="https://avatars2.githubusercontent.com/u/6342851?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Aleksei Trifonov</b></sub></a><br /><a href="#content-avrong" title="Content">🖋</a></td>
+    <td align="center"><a href="https://drn.ie"><img src="https://avatars2.githubusercontent.com/u/411136?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Darren Meehan</b></sub></a><br /><a href="#content-Darrenmeehan" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/jihchi"><img src="https://avatars1.githubusercontent.com/u/87983?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jihchi Lee</b></sub></a><br /><a href="#content-jihchi" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/bertonha"><img src="https://avatars3.githubusercontent.com/u/1225902?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Christofer Bertonha</b></sub></a><br /><a href="#content-bertonha" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/apatniv"><img src="https://avatars2.githubusercontent.com/u/22565917?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Vivek Bharath Akupatni</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=apatniv" title="Code">💻</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apatniv" title="Tests">⚠️</a></td>
+    <td align="center"><a href="https://github.com/DiD92"><img src="https://avatars3.githubusercontent.com/u/6002416?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Dídac Sementé Fernández</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=DiD92" title="Code">💻</a> <a href="#content-DiD92" title="Content">🖋</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/wrobstory"><img src="https://avatars3.githubusercontent.com/u/2601457?v=4" width="100px;" alt=""/><br /><sub><b>Rob Story</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=wrobstory" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/siobhanjacobson"><img src="https://avatars2.githubusercontent.com/u/28983835?v=4" width="100px;" alt=""/><br /><sub><b>Siobhan Jacobson</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=siobhanjacobson" title="Code">💻</a></td>
-    <td align="center"><a href="https://www.linkedin.com/in/evancarroll/"><img src="https://avatars2.githubusercontent.com/u/19922?v=4" width="100px;" alt=""/><br /><sub><b>Evan Carroll</b></sub></a><br /><a href="#content-EvanCarroll" title="Content">🖋</a></td>
-    <td align="center"><a href="http://www.jawaadmahmood.com"><img src="https://avatars3.githubusercontent.com/u/95606?v=4" width="100px;" alt=""/><br /><sub><b>Jawaad Mahmood</b></sub></a><br /><a href="#content-jmahmood" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/GaurangTandon"><img src="https://avatars1.githubusercontent.com/u/6308683?v=4" width="100px;" alt=""/><br /><sub><b>Gaurang Tandon</b></sub></a><br /><a href="#content-GaurangTandon" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/dev-cyprium"><img src="https://avatars1.githubusercontent.com/u/6002628?v=4" width="100px;" alt=""/><br /><sub><b>Stefan Kupresak</b></sub></a><br /><a href="#content-dev-cyprium" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/greg-el"><img src="https://avatars3.githubusercontent.com/u/45019882?v=4" width="100px;" alt=""/><br /><sub><b>Greg Leonard</b></sub></a><br /><a href="#content-greg-el" title="Content">🖋</a></td>
-    <td align="center"><a href="https://ryanpcmcquen.org"><img src="https://avatars3.githubusercontent.com/u/772937?v=4" width="100px;" alt=""/><br /><sub><b>Ryan McQuen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ryanpcmcquen" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/wrobstory"><img src="https://avatars3.githubusercontent.com/u/2601457?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rob Story</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=wrobstory" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/siobhanjacobson"><img src="https://avatars2.githubusercontent.com/u/28983835?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Siobhan Jacobson</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=siobhanjacobson" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.linkedin.com/in/evancarroll/"><img src="https://avatars2.githubusercontent.com/u/19922?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Evan Carroll</b></sub></a><br /><a href="#content-EvanCarroll" title="Content">🖋</a></td>
+    <td align="center"><a href="http://www.jawaadmahmood.com"><img src="https://avatars3.githubusercontent.com/u/95606?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jawaad Mahmood</b></sub></a><br /><a href="#content-jmahmood" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/GaurangTandon"><img src="https://avatars1.githubusercontent.com/u/6308683?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Gaurang Tandon</b></sub></a><br /><a href="#content-GaurangTandon" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/dev-cyprium"><img src="https://avatars1.githubusercontent.com/u/6002628?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Stefan Kupresak</b></sub></a><br /><a href="#content-dev-cyprium" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/greg-el"><img src="https://avatars3.githubusercontent.com/u/45019882?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Greg Leonard</b></sub></a><br /><a href="#content-greg-el" title="Content">🖋</a></td>
+    <td align="center"><a href="https://ryanpcmcquen.org"><img src="https://avatars3.githubusercontent.com/u/772937?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ryan McQuen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ryanpcmcquen" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/AnnikaCodes"><img src="https://avatars3.githubusercontent.com/u/56906084?v=4" width="100px;" alt=""/><br /><sub><b>Annika</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAnnikaCodes" title="Reviewed Pull Requests">👀</a></td>
-    <td align="center"><a href="https://darnuria.eu"><img src="https://avatars1.githubusercontent.com/u/2827553?v=4" width="100px;" alt=""/><br /><sub><b>Axel Viala</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=darnuria" title="Code">💻</a></td>
-    <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
-    <td align="center"><a href="https://codingthemsoftly.com"><img src="https://avatars1.githubusercontent.com/u/17479099?v=4" width="100px;" alt=""/><br /><sub><b>Caleb Webber</b></sub></a><br /><a href="#maintenance-seeplusplus" title="Maintenance">🚧</a></td>
-    <td align="center"><a href="https://github.com/pcn"><img src="https://avatars2.githubusercontent.com/u/1056756?v=4" width="100px;" alt=""/><br /><sub><b>Peter N</b></sub></a><br /><a href="#maintenance-pcn" title="Maintenance">🚧</a></td>
-    <td align="center"><a href="https://github.com/seancad"><img src="https://avatars1.githubusercontent.com/u/47405611?v=4" width="100px;" alt=""/><br /><sub><b>seancad</b></sub></a><br /><a href="#maintenance-seancad" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/AnnikaCodes"><img src="https://avatars3.githubusercontent.com/u/56906084?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Annika</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAnnikaCodes" title="Reviewed Pull Requests">👀</a></td>
+    <td align="center"><a href="https://darnuria.eu"><img src="https://avatars1.githubusercontent.com/u/2827553?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Axel Viala</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=darnuria" title="Code">💻</a></td>
+    <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
+    <td align="center"><a href="https://codingthemsoftly.com"><img src="https://avatars1.githubusercontent.com/u/17479099?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Caleb Webber</b></sub></a><br /><a href="#maintenance-seeplusplus" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/pcn"><img src="https://avatars2.githubusercontent.com/u/1056756?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Peter N</b></sub></a><br /><a href="#maintenance-pcn" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/seancad"><img src="https://avatars1.githubusercontent.com/u/47405611?v=4?s=100" width="100px;" alt=""/><br /><sub><b>seancad</b></sub></a><br /><a href="#maintenance-seancad" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="http://willhayworth.com"><img src="https://avatars3.githubusercontent.com/u/181174?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Will Hayworth</b></sub></a><br /><a href="#content-wsh" title="Content">🖋</a></td>
   </tr>
 </table>
 
-<!-- markdownlint-enable -->
+<!-- markdownlint-restore -->
 <!-- prettier-ignore-end -->
+
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!

From 6df08b411bc09fd10d510be74c80e9cc6164e145 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 4 Jan 2021 13:12:11 +0000
Subject: [PATCH 035/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 1549aa45..d2b0fae1 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -655,6 +655,15 @@
       "contributions": [
         "maintenance"
       ]
+    },
+    {
+      "login": "wsh",
+      "name": "Will Hayworth",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/181174?v=4",
+      "profile": "http://willhayworth.com",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 10965920fbdf8a1efc85bed869e55a1787006404 Mon Sep 17 00:00:00 2001
From: Marius Ungureanu <therzok@gmail.com>
Date: Wed, 6 Jan 2021 11:12:33 +0200
Subject: [PATCH 036/126] fix(move_semantics4): Small readbility improvement
 (#617)

* Small readbility improvement move_semantics4 doc

* Remove `an` as it refers to the argument
---
 exercises/move_semantics/move_semantics4.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/move_semantics/move_semantics4.rs b/exercises/move_semantics/move_semantics4.rs
index a1c4a413..6308c296 100644
--- a/exercises/move_semantics/move_semantics4.rs
+++ b/exercises/move_semantics/move_semantics4.rs
@@ -18,7 +18,7 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-// `fill_vec()` no longer take `vec: Vec<i32>` as argument
+// `fill_vec()` no longer takes `vec: Vec<i32>` as argument
 fn fill_vec() -> Vec<i32> {
     let mut vec = vec;
 

From 7857b0a689b0847f48d8c14cbd1865e3b812d5ca Mon Sep 17 00:00:00 2001
From: Christian Zeller <chrizel@posteo.de>
Date: Wed, 6 Jan 2021 13:47:20 +0100
Subject: [PATCH 037/126] fix(threads1): line number correction

---
 exercises/threads/threads1.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/threads/threads1.rs b/exercises/threads/threads1.rs
index b475b4a1..f31b317e 100644
--- a/exercises/threads/threads1.rs
+++ b/exercises/threads/threads1.rs
@@ -1,6 +1,6 @@
 // threads1.rs
 // Make this compile! Execute `rustlings hint threads1` for hints :)
-// The idea is the thread spawned on line 21 is completing jobs while the main thread is
+// The idea is the thread spawned on line 22 is completing jobs while the main thread is
 // monitoring progress until 10 jobs are completed. Because of the difference between the
 // spawned threads' sleep time, and the waiting threads sleep time, when you see 6 lines
 // of "waiting..." and the program ends without timing out when running,

From 621816fb561a9501aa15e8c3674ccdff3b2b24fe Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Wed, 6 Jan 2021 15:54:33 +0000
Subject: [PATCH 038/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index b67793d4..f489f93d 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-71-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-72-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -256,6 +256,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/pcn"><img src="https://avatars2.githubusercontent.com/u/1056756?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Peter N</b></sub></a><br /><a href="#maintenance-pcn" title="Maintenance">🚧</a></td>
     <td align="center"><a href="https://github.com/seancad"><img src="https://avatars1.githubusercontent.com/u/47405611?v=4?s=100" width="100px;" alt=""/><br /><sub><b>seancad</b></sub></a><br /><a href="#maintenance-seancad" title="Maintenance">🚧</a></td>
     <td align="center"><a href="http://willhayworth.com"><img src="https://avatars3.githubusercontent.com/u/181174?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Will Hayworth</b></sub></a><br /><a href="#content-wsh" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/chrizel"><img src="https://avatars3.githubusercontent.com/u/20802?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Christian Zeller</b></sub></a><br /><a href="#content-chrizel" title="Content">🖋</a></td>
   </tr>
 </table>
 

From c24a78ae94b0e8527ee75908edeea136a7a3dbeb Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Wed, 6 Jan 2021 15:54:34 +0000
Subject: [PATCH 039/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index d2b0fae1..46e68ae5 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -664,6 +664,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "chrizel",
+      "name": "Christian Zeller",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/20802?v=4",
+      "profile": "https://github.com/chrizel",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From fea86c29d6b0b29513e1cfb56b9eab5d4dcd121e Mon Sep 17 00:00:00 2001
From: fmoko <mokou@posteo.de>
Date: Fri, 8 Jan 2021 14:01:04 +0100
Subject: [PATCH 040/126] chore: Remove Readme GIF

---
 README.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/README.md b/README.md
index f489f93d..987bb839 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,3 @@
-![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
 [![All Contributors](https://img.shields.io/badge/all_contributors-72-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->

From 5a0521e92c80c43d6451fcc520fd68e7f56106f8 Mon Sep 17 00:00:00 2001
From: Sang-Heon Jeon <ekffu200098@gmail.com>
Date: Sat, 9 Jan 2021 00:07:13 +0900
Subject: [PATCH 041/126] feat(from_str) : add test for checking unnecessary
 trailing value

---
 exercises/conversions/from_str.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/exercises/conversions/from_str.rs b/exercises/conversions/from_str.rs
index af9eee6d..70ed1796 100644
--- a/exercises/conversions/from_str.rs
+++ b/exercises/conversions/from_str.rs
@@ -82,4 +82,16 @@ mod tests {
     fn missing_name_and_invalid_age() {
         ",one".parse::<Person>().unwrap();
     }
+
+    #[test]
+    #[should_panic]
+    fn trailing_comma() {
+        "John,32,".parse::<Person>().unwrap();
+    }
+
+    #[test]
+    #[should_panic]
+    fn trailing_comma_and_some_string() {
+        "John,32,man".parse::<Person>().unwrap();
+    }
 }

From 4f1374a6e7dd76d0f8769adf51495d5d0f9ea8a1 Mon Sep 17 00:00:00 2001
From: Sang-Heon Jeon <ekffu200098@gmail.com>
Date: Sat, 9 Jan 2021 00:08:38 +0900
Subject: [PATCH 042/126] feat(from_into) : add test for checking unnecessary
 trailing value

---
 exercises/conversions/from_into.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/exercises/conversions/from_into.rs b/exercises/conversions/from_into.rs
index f24cf61b..9d84174d 100644
--- a/exercises/conversions/from_into.rs
+++ b/exercises/conversions/from_into.rs
@@ -115,4 +115,18 @@ mod tests {
         assert_eq!(p.name, "John");
         assert_eq!(p.age, 30);
     }
+
+    #[test]
+    fn test_trailing_comma() {
+        let p: Person = Person::from("Mike,32,");
+        assert_eq!(p.name, "John");
+        assert_eq!(p.age, 30);
+    }
+
+    #[test]
+    fn test_trailing_comma_and_some_string() {
+        let p: Person = Person::from("Mike,32,man");
+        assert_eq!(p.name, "John");
+        assert_eq!(p.age, 30);
+    }
 }

From 0b9220c1fc5ae32438f64bf2f5bf5f47d33e3f3f Mon Sep 17 00:00:00 2001
From: Abdou Seck <djily02016@gmail.com>
Date: Sat, 12 Dec 2020 13:45:37 -0500
Subject: [PATCH 043/126] Add looks_done method to Exercise to expose a
 resolution state

---
 src/exercise.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/exercise.rs b/src/exercise.rs
index 283b2b90..7afa230a 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -232,6 +232,16 @@ path = "{}.rs""#,
 
         State::Pending(context)
     }
+
+    // Check that the exercise looks to be solved using self.state()
+    // This is not the best way to check since
+    // the user can just remove the "I AM NOT DONE" string fromm the file
+    // without actually having solved anything.
+    // The only other way to truly check this would to compile and run
+    // the exercise; which would be both costly and counterintuitive
+    pub fn looks_done(&self) -> bool {
+        self.state() == State::Done
+    }
 }
 
 impl Display for Exercise {

From 8bbe4ff1385c5c169c90cd3ff9253f9a91daaf8e Mon Sep 17 00:00:00 2001
From: Abdou Seck <djily02016@gmail.com>
Date: Sat, 12 Dec 2020 13:48:25 -0500
Subject: [PATCH 044/126] feat(cli): Improve the list command with options, and
 then some

1.
`rustlings list` should now display more than just the exercise names.
Information such as file paths and exercises statuses should be displayed.
The `--paths` option limits the displayed fields to only the path names; while the `--names`
option limits the displayed fields to only exercise names.
You can also control which exercises are displayed, by using the `--filter` option, or
the `--solved` or `--unsolved` flags.

Some use cases:
- Fetching pending exercise files with the keyword "conversion" to pass to my editor:
```sh
vim $(rustlings list --filter "conversion" --paths --unsolved)
```

- Fetching exercise names with keyword "conversion" to pass to `rustlings run`:
```sh
for exercise in $(rustlings list --filter "conversion" --names)
do
    rustlings run ${exercise}
done
```

2.
This should also fix #465, and will likely fix #585, as well.
That bug mentioned in those issues has to do with the way the `watch` command handler fetches the pending exercises.
Going forward, the least recently updated exercises along with all the other exercises in a pending state are fetched.
---
 src/main.rs                   | 132 ++++++++++++++++++++++++++++------
 tests/fixture/state/info.toml |   7 ++
 tests/integration_tests.rs    |  78 ++++++++++++++++++++
 3 files changed, 197 insertions(+), 20 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index bf35e4fb..75a9cec1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,7 +7,7 @@ use notify::DebouncedEvent;
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
 use std::ffi::OsStr;
 use std::fs;
-use std::io;
+use std::io::{self, prelude::*};
 use std::path::Path;
 use std::process::{Command, Stdio};
 use std::sync::mpsc::channel;
@@ -58,6 +58,45 @@ fn main() {
             SubCommand::with_name("list")
                 .alias("l")
                 .about("Lists the exercises available in rustlings")
+                .arg(
+                    Arg::with_name("paths")
+                        .long("paths")
+                        .short("p")
+                        .conflicts_with("names")
+                        .help("Show only the paths of the exercises")
+                )
+                .arg(
+                    Arg::with_name("names")
+                        .long("names")
+                        .short("n")
+                        .conflicts_with("paths")
+                        .help("Show only the names of the exercises")
+                )
+                .arg(
+                    Arg::with_name("filter")
+                        .long("filter")
+                        .short("f")
+                        .takes_value(true)
+                        .empty_values(false)
+                        .help(
+                            "Provide a string to match the exercise names.\
+                            \nComma separated patterns are acceptable."
+                        )
+                )
+                .arg(
+                    Arg::with_name("unsolved")
+                        .long("unsolved")
+                        .short("u")
+                        .conflicts_with("solved")
+                        .help("Display only exercises not yet solved")
+                )
+                .arg(
+                    Arg::with_name("solved")
+                        .long("solved")
+                        .short("s")
+                        .conflicts_with("unsolved")
+                        .help("Display only exercises that have been solved")
+                )
         )
         .get_matches();
 
@@ -93,9 +132,51 @@ fn main() {
     let exercises = toml::from_str::<ExerciseList>(toml_str).unwrap().exercises;
     let verbose = matches.is_present("nocapture");
 
-    if matches.subcommand_matches("list").is_some() {
-        exercises.iter().for_each(|e| println!("{}", e.name));
+    // Handle the list command
+    if let Some(list_m) = matches.subcommand_matches("list") {
+        if ["paths", "names"].iter().all(|k| !list_m.is_present(k)) {
+            println!("{:<17}\t{:<46}\t{:<7}", "Name", "Path", "Status");
+        }
+        let filters = list_m.value_of("filter").unwrap_or_default().to_lowercase();
+        exercises.iter().for_each(|e| {
+            let fname = format!("{}", e.path.display());
+            let filter_cond = filters
+                .split(',')
+                .filter(|f| f.trim().len() > 0)
+                .any(|f| e.name.contains(&f) || fname.contains(&f));
+            let status = if e.looks_done() { "Done" } else { "Pending" };
+            let solve_cond = {
+                (e.looks_done() && list_m.is_present("solved"))
+                    || (!e.looks_done() && list_m.is_present("unsolved"))
+                    || (!list_m.is_present("solved") && !list_m.is_present("unsolved"))
+            };
+            if solve_cond && (filter_cond || !list_m.is_present("filter")) {
+                let line = if list_m.is_present("paths") {
+                    format!("{}\n", fname)
+                } else if list_m.is_present("names") {
+                    format!("{}\n", e.name)
+                } else {
+                    format!("{:<17}\t{:<46}\t{:<7}\n", e.name, fname, status)
+                };
+                // Somehow using println! leads to the binary panicking
+                // when its output is piped.
+                // So, we're handling a Broken Pipe error and exiting with 0 anyway
+                let stdout = std::io::stdout();
+                {
+                    let mut handle = stdout.lock();
+                    handle.write_all(line.as_bytes()).unwrap_or_else(|e| {
+                        match e.kind() {
+                            std::io::ErrorKind::BrokenPipe => std::process::exit(0),
+                            _ => std::process::exit(1),
+                        };
+                    });
+                }
+            }
+        });
+        std::process::exit(0);
     }
+
+    // Handle the run command
     if let Some(ref matches) = matches.subcommand_matches("run") {
         let name = matches.value_of("name").unwrap();
 
@@ -123,13 +204,18 @@ fn main() {
         println!("{}", exercise.hint);
     }
 
+    // Handle the verify command
     if matches.subcommand_matches("verify").is_some() {
         verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
     }
 
+    // Handle the watch command
     if matches.subcommand_matches("watch").is_some() {
         if let Err(e) = watch(&exercises, verbose) {
-            println!("Error: Could not watch your progess. Error message was {:?}.", e);
+            println!(
+                "Error: Could not watch your progess. Error message was {:?}.",
+                e
+            );
             println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
             std::process::exit(1);
         }
@@ -138,24 +224,24 @@ fn main() {
             emoji = Emoji("🎉", "★")
         );
         println!();
-        println!("+----------------------------------------------------+");     
-        println!("|          You made it to the Fe-nish line!          |");       
-        println!("+--------------------------  ------------------------+");       
+        println!("+----------------------------------------------------+");
+        println!("|          You made it to the Fe-nish line!          |");
+        println!("+--------------------------  ------------------------+");
         println!("                          \\/                         ");
-        println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");        
-        println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");        
-        println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");        
-        println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");        
-        println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");        
-        println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");      
-        println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");    
-        println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");  
+        println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");
+        println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");
+        println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");
+        println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");
+        println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");
+        println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");
+        println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");
+        println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");
         println!("           ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒         ");
         println!("             ▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒           ");
-        println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");  
-        println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");    
-        println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");    
-        println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");    
+        println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");
+        println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");
+        println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");
+        println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");
         println!("           ▒▒  ▒▒                      ▒▒  ▒▒         ");
         println!();
         println!("We hope you enjoyed learning about the various aspects of Rust!");
@@ -223,7 +309,13 @@ fn watch(exercises: &[Exercise], verbose: bool) -> notify::Result<()> {
                         let filepath = b.as_path().canonicalize().unwrap();
                         let pending_exercises = exercises
                             .iter()
-                            .skip_while(|e| !filepath.ends_with(&e.path));
+                            .skip_while(|e| !filepath.ends_with(&e.path))
+                            // .filter(|e| filepath.ends_with(&e.path))
+                            .chain(
+                                exercises
+                                    .iter()
+                                    .filter(|e| !e.looks_done() && !filepath.ends_with(&e.path))
+                            );
                         clear_screen();
                         match verify(pending_exercises, verbose) {
                             Ok(_) => return Ok(()),
diff --git a/tests/fixture/state/info.toml b/tests/fixture/state/info.toml
index 7bfc697e..547b3a48 100644
--- a/tests/fixture/state/info.toml
+++ b/tests/fixture/state/info.toml
@@ -9,3 +9,10 @@ name = "pending_test_exercise"
 path = "pending_test_exercise.rs"
 mode = "test"
 hint = """"""
+
+[[exercises]]
+name = "finished_exercise"
+path = "finished_exercise.rs"
+mode = "compile"
+hint = """"""
+
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 2baf9b86..f5211b64 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -181,3 +181,81 @@ fn run_single_test_success_without_output() {
         .code(0)
         .stdout(predicates::str::contains("THIS TEST TOO SHALL PAS").not());
 }
+
+#[test]
+fn run_rustlings_list() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list"])
+        .current_dir("tests/fixture/success")
+        .assert()
+        .success();
+}
+
+#[test]
+fn run_rustlings_list_conflicting_display_options() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list", "--names", "--paths"])
+        .current_dir("tests/fixture/success")
+        .assert()
+        .failure();
+}
+
+#[test]
+fn run_rustlings_list_conflicting_solve_options() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list", "--solved", "--unsolved"])
+        .current_dir("tests/fixture/success")
+        .assert()
+        .failure();
+}
+
+#[test]
+fn run_rustlings_list_no_pending() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list"])
+        .current_dir("tests/fixture/success")
+        .assert()
+        .success()
+        .stdout(predicates::str::contains("Pending").not());
+}
+
+#[test]
+fn run_rustlings_list_both_done_and_pending() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list"])
+        .current_dir("tests/fixture/state")
+        .assert()
+        .success()
+        .stdout(
+            predicates::str::contains("Done")
+                .and(predicates::str::contains("Pending"))
+        );
+}
+
+#[test]
+fn run_rustlings_list_without_pending() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list", "--solved"])
+        .current_dir("tests/fixture/state")
+        .assert()
+        .success()
+        .stdout(predicates::str::contains("Pending").not());
+}
+
+#[test]
+fn run_rustlings_list_without_done() {
+    Command::cargo_bin("rustlings")
+        .unwrap()
+        .args(&["list", "--unsolved"])
+        .current_dir("tests/fixture/state")
+        .assert()
+        .success()
+        .stdout(predicates::str::contains("Done").not());
+}
+

From 9f988bfe29e1146cd7dc95c68dd6863e77433553 Mon Sep 17 00:00:00 2001
From: mokou <mokou@posteo.de>
Date: Sun, 17 Jan 2021 13:00:50 +0100
Subject: [PATCH 045/126] docs: Remove duplicate uninstallation section

---
 README.md | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/README.md b/README.md
index 987bb839..369bfab7 100644
--- a/README.md
+++ b/README.md
@@ -112,13 +112,6 @@ After every couple of sections, there will be a quiz that'll test your knowledge
 
 Once you've completed Rustlings, put your new knowledge to good use! Continue practicing your Rust skills by building your own projects, contributing to Rustlings, or finding other open-source projects to contribute to.
 
-If you'd like to uninstall Rustlings, you can do so by invoking cargo and removing the rustlings directory:
-
-```bash
-cargo uninstall rustlings
-rm -r rustlings/ # or on Windows: rmdir /s rustlings
-```
-
 ## Uninstalling Rustlings
 
 If you want to remove Rustlings from your system, there's two steps. First, you'll need to remove the exercises folder that the install script created

From 15e71535f37cfaed36e22eb778728d186e2104ab Mon Sep 17 00:00:00 2001
From: Jean-Francois Chevrette <jfchevrette@gmail.com>
Date: Thu, 21 Jan 2021 07:55:22 -0500
Subject: [PATCH 046/126] fix(from_str): test for error instead of
 unwrap/should_panic

---
 exercises/conversions/from_str.rs | 36 +++++++++++++------------------
 1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/exercises/conversions/from_str.rs b/exercises/conversions/from_str.rs
index 70ed1796..558a9033 100644
--- a/exercises/conversions/from_str.rs
+++ b/exercises/conversions/from_str.rs
@@ -11,15 +11,17 @@ struct Person {
 }
 
 // I AM NOT DONE
+
 // Steps:
-// 1. If the length of the provided string is 0, then return an error
+// 1. If the length of the provided string is 0 an error should be returned
 // 2. Split the given string on the commas present in it
-// 3. Extract the first element from the split operation and use it as the name
-// 4. If the name is empty, then return an error
+// 3. Only 2 elements should returned from the split, otherwise return an error
+// 4. Extract the first element from the split operation and use it as the name
 // 5. Extract the other element from the split operation and parse it into a `usize` as the age
 //    with something like `"4".parse::<usize>()`.
-// If while parsing the age, something goes wrong, then return an error
-// Otherwise, then return a Result of a Person object
+// 5. If while extracting the name and the age something goes wrong an error should be returned
+// If everything goes well, then return a Result of a Person object
+
 impl FromStr for Person {
     type Err = String;
     fn from_str(s: &str) -> Result<Person, Self::Err> {
@@ -48,50 +50,42 @@ mod tests {
         assert_eq!(p.age, 32);
     }
     #[test]
-    #[should_panic]
     fn missing_age() {
-        "John,".parse::<Person>().unwrap();
+        assert!("John,".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn invalid_age() {
-        "John,twenty".parse::<Person>().unwrap();
+        assert!("John,twenty".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_comma_and_age() {
-        "John".parse::<Person>().unwrap();
+        assert!("John".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_name() {
-        ",1".parse::<Person>().unwrap();
+        assert!(",1".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_name_and_age() {
-        ",".parse::<Person>().unwrap();
+        assert!(",".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn missing_name_and_invalid_age() {
-        ",one".parse::<Person>().unwrap();
+        assert!(",one".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn trailing_comma() {
-        "John,32,".parse::<Person>().unwrap();
+        assert!("John,32,".parse::<Person>().is_err());
     }
 
     #[test]
-    #[should_panic]
     fn trailing_comma_and_some_string() {
-        "John,32,man".parse::<Person>().unwrap();
+        assert!("John,32,man".parse::<Person>().is_err());
     }
 }

From 52bde71166740880da2206553df790d47cecba54 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 22 Jan 2021 12:11:33 +0000
Subject: [PATCH 047/126] docs: update README.md [skip ci]

---
 README.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 369bfab7..af97f556 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-72-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-73-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -250,6 +250,9 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="http://willhayworth.com"><img src="https://avatars3.githubusercontent.com/u/181174?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Will Hayworth</b></sub></a><br /><a href="#content-wsh" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/chrizel"><img src="https://avatars3.githubusercontent.com/u/20802?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Christian Zeller</b></sub></a><br /><a href="#content-chrizel" title="Content">🖋</a></td>
   </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/jfchevrette"><img src="https://avatars.githubusercontent.com/u/3001?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jean-Francois Chevrette</b></sub></a><br /><a href="#content-jfchevrette" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jfchevrette" title="Code">💻</a></td>
+  </tr>
 </table>
 
 <!-- markdownlint-restore -->

From 6102e612fa3f6255cccea4c9016078f6ea007be0 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 22 Jan 2021 12:11:34 +0000
Subject: [PATCH 048/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 46e68ae5..ea3d7ca2 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -673,6 +673,16 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "jfchevrette",
+      "name": "Jean-Francois Chevrette",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3001?v=4",
+      "profile": "https://github.com/jfchevrette",
+      "contributions": [
+        "content",
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From cddc1e86e7ec744ee644cc774a4887b1a0ded3e8 Mon Sep 17 00:00:00 2001
From: John Baber-Lucero <github@frundle.com>
Date: Sat, 30 Jan 2021 16:12:06 +0000
Subject: [PATCH 049/126] fix(info): Fix typo (#635)

Co-authored-by: John Baber-Lucero <git@frundle.com>
---
 info.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/info.toml b/info.toml
index 23c64917..f0fed934 100644
--- a/info.toml
+++ b/info.toml
@@ -284,7 +284,7 @@ hint = """
 Rust has more than one type of struct. Three actually, all variants are used to package related data together.
 There are normal (or classic) structs. These are named collections of related data stored in fields.
 Tuple structs are basically just named tuples.
-Finally, Unit structs. These don't have and fields and are useful for generics.
+Finally, Unit structs. These don't have any fields and are useful for generics.
 
 In this exercise you need to complete and implement one of each kind.
 Read more about structs in The Book: https://doc.rust-lang.org/book/ch05-01-defining-structs.html"""

From 75802c14b2dbfbbf65139608f19cb94dba6d7a2c Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sat, 30 Jan 2021 16:12:27 +0000
Subject: [PATCH 050/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index af97f556..c2e598c1 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-73-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-74-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -252,6 +252,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/jfchevrette"><img src="https://avatars.githubusercontent.com/u/3001?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jean-Francois Chevrette</b></sub></a><br /><a href="#content-jfchevrette" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jfchevrette" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/jbaber"><img src="https://avatars.githubusercontent.com/u/1908117?v=4?s=100" width="100px;" alt=""/><br /><sub><b>John Baber-Lucero</b></sub></a><br /><a href="#content-jbaber" title="Content">🖋</a></td>
   </tr>
 </table>
 

From c1abd13b5c026643b5dddc85b3aa546ef75243d6 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sat, 30 Jan 2021 16:12:28 +0000
Subject: [PATCH 051/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index ea3d7ca2..9cdf6b08 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -683,6 +683,15 @@
         "content",
         "code"
       ]
+    },
+    {
+      "login": "jbaber",
+      "name": "John Baber-Lucero",
+      "avatar_url": "https://avatars.githubusercontent.com/u/1908117?v=4",
+      "profile": "https://github.com/jbaber",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From cc266d7d80b91e79df3f61984f231b7f1587218e Mon Sep 17 00:00:00 2001
From: Tal <3195851+tal-zvon@users.noreply.github.com>
Date: Sun, 7 Feb 2021 04:22:13 -0700
Subject: [PATCH 052/126] fix(move_semantics4): Remove redundant "instead"
 (#640)

---
 exercises/move_semantics/move_semantics4.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/move_semantics/move_semantics4.rs b/exercises/move_semantics/move_semantics4.rs
index 6308c296..2a23c710 100644
--- a/exercises/move_semantics/move_semantics4.rs
+++ b/exercises/move_semantics/move_semantics4.rs
@@ -1,6 +1,6 @@
 // move_semantics4.rs
 // Refactor this code so that instead of having `vec0` and creating the vector
-// in `fn main`, we instead create it within `fn fill_vec` and transfer the
+// in `fn main`, we create it within `fn fill_vec` and transfer the
 // freshly created vector from fill_vec to its caller.
 // Execute `rustlings hint move_semantics4` for hints!
 

From 1f9d00685836cbf639a518b5612e7e16d669bf48 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sun, 7 Feb 2021 11:22:32 +0000
Subject: [PATCH 053/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index c2e598c1..fe61f6f4 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-74-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-75-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -253,6 +253,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://github.com/jfchevrette"><img src="https://avatars.githubusercontent.com/u/3001?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jean-Francois Chevrette</b></sub></a><br /><a href="#content-jfchevrette" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jfchevrette" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/jbaber"><img src="https://avatars.githubusercontent.com/u/1908117?v=4?s=100" width="100px;" alt=""/><br /><sub><b>John Baber-Lucero</b></sub></a><br /><a href="#content-jbaber" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/tal-zvon"><img src="https://avatars.githubusercontent.com/u/3195851?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Tal</b></sub></a><br /><a href="#content-tal-zvon" title="Content">🖋</a></td>
   </tr>
 </table>
 

From f1d2b3a39a676ae25cc0e4fb18f582441bc239e2 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sun, 7 Feb 2021 11:22:33 +0000
Subject: [PATCH 054/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 9cdf6b08..6db7a29b 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -692,6 +692,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "tal-zvon",
+      "name": "Tal",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3195851?v=4",
+      "profile": "https://github.com/tal-zvon",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 726805f064659f8cc2612974eb6d21690378cabc Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Tue, 9 Feb 2021 17:43:53 -0500
Subject: [PATCH 055/126] docs: Fixed grammar in contributing.md.

---
 CONTRIBUTING.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d566df08..2ca0e341 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -26,12 +26,12 @@ isn't really that complicated since the bulk of the work is done by `rustc`.
 <a name="addex"></a>
 ### Adding an exercise
 
-First step is to add the exercise! Call it `exercises/yourTopic/yourTopicN.rs`, make sure to
+The first step is to add the exercise! Name the file `exercises/yourTopic/yourTopicN.rs`, make sure to
 put in some helpful links, and link to sections of the book in `exercises/yourTopic/README.md`.
 
-Next you want to make sure it runs when using `rustlings`. All exercises are stored in `info.toml`, under the `exercises` array. They're ordered by the order they're ran when using `rustlings verify`.
+Next make sure it runs with `rustlings`. The exercise metadata is stored in `info.toml`, under the `exercises` array. The order of the `exercises` array determines the order the exercises are run by `rustlings verify`.
 
-You want to make sure where in the file you add your exercise. If you're not sure, add it at the bottom and ask in your pull request. To add an exercise, edit the file like this:
+Add the metadata for your exercise in the correct order in the `exercises` array. If you are unsure of the correct ordering, add it at the bottom and ask in your pull request. The exercise metadata should contain the following:
 ```diff
   ...
 + [[exercises]]

From 2e84f34cf375fa3d12c73d1f28d68f0be9de3dc4 Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Tue, 9 Feb 2021 18:21:18 -0500
Subject: [PATCH 056/126] chore: Updated source to follow clippy suggestions.

---
 src/main.rs                | 2 +-
 tests/integration_tests.rs | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 75a9cec1..50e4a386 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -142,7 +142,7 @@ fn main() {
             let fname = format!("{}", e.path.display());
             let filter_cond = filters
                 .split(',')
-                .filter(|f| f.trim().len() > 0)
+                .filter(|f| !f.trim().is_empty())
                 .any(|f| e.name.contains(&f) || fname.contains(&f));
             let status = if e.looks_done() { "Done" } else { "Pending" };
             let solve_cond = {
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index f5211b64..1bd3bf7e 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -131,7 +131,7 @@ fn all_exercises_require_confirmation() {
             file.read_to_string(&mut s).unwrap();
             s
         };
-        source.matches("// I AM NOT DONE").next().expect(&format!(
+        source.matches("// I AM NOT DONE").next().unwrap_or_else(|| panic!(
             "There should be an `I AM NOT DONE` annotation in {:?}",
             path
         ));

From d65b4a9a93477745e206de11e1634ffe3cb3a6e6 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Wed, 10 Feb 2021 09:36:47 +0000
Subject: [PATCH 057/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index fe61f6f4..9e617eba 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-75-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-76-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -254,6 +254,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/jfchevrette"><img src="https://avatars.githubusercontent.com/u/3001?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jean-Francois Chevrette</b></sub></a><br /><a href="#content-jfchevrette" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jfchevrette" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/jbaber"><img src="https://avatars.githubusercontent.com/u/1908117?v=4?s=100" width="100px;" alt=""/><br /><sub><b>John Baber-Lucero</b></sub></a><br /><a href="#content-jbaber" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/tal-zvon"><img src="https://avatars.githubusercontent.com/u/3195851?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Tal</b></sub></a><br /><a href="#content-tal-zvon" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/apogeeoak"><img src="https://avatars.githubusercontent.com/u/59737221?v=4?s=100" width="100px;" alt=""/><br /><sub><b>apogeeoak</b></sub></a><br /><a href="#content-apogeeoak" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apogeeoak" title="Code">💻</a></td>
   </tr>
 </table>
 

From f5158ece1a9d9896f089a352f8a2bd7502890864 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Wed, 10 Feb 2021 09:36:48 +0000
Subject: [PATCH 058/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 6db7a29b..c4e68a15 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -701,6 +701,16 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "apogeeoak",
+      "name": "apogeeoak",
+      "avatar_url": "https://avatars.githubusercontent.com/u/59737221?v=4",
+      "profile": "https://github.com/apogeeoak",
+      "contributions": [
+        "content",
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From b29ea17ea94d1862114af2cf5ced0e09c197dc35 Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Wed, 10 Feb 2021 18:03:29 -0500
Subject: [PATCH 059/126] feat: Added iterators5.rs exercise.

---
 .../standard_library_types/iterators5.rs      | 113 ++++++++++++++++++
 info.toml                                     |  15 +++
 2 files changed, 128 insertions(+)
 create mode 100644 exercises/standard_library_types/iterators5.rs

diff --git a/exercises/standard_library_types/iterators5.rs b/exercises/standard_library_types/iterators5.rs
new file mode 100644
index 00000000..65c50e62
--- /dev/null
+++ b/exercises/standard_library_types/iterators5.rs
@@ -0,0 +1,113 @@
+// iterators5.rs
+
+// Rustling progress is modelled using a hash map. The name of the exercise is
+// the key and the progress is the value. Two counting functions were created
+// to count the number of exercises with a given progress. These counting
+// functions use imperative style for loops. Recreate this counting
+// functionality using iterators.
+// Execute `rustlings hint iterators5` for hints.
+//
+// Make the code compile and the tests pass.
+
+// I AM NOT DONE
+
+use std::collections::HashMap;
+
+#[derive(PartialEq, Eq)]
+enum Progress {
+    None,
+    Some,
+    Complete,
+}
+
+fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
+    let mut count = 0;
+    for val in map.values() {
+        if val == &value {
+            count += 1;
+        }
+    }
+    count
+}
+
+fn count(map: &HashMap<String, Progress>, value: Progress) -> usize {
+}
+
+fn count_stack_for(stack: &[HashMap<String, Progress>], value: Progress) -> usize {
+    let mut count = 0;
+    for map in stack {
+        for val in map.values() {
+            if val == &value {
+                count += 1;
+            }
+        }
+    }
+    count
+}
+
+fn count_stack(stack: &[HashMap<String, Progress>], value: Progress) -> usize {
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn count_complete() {
+        let map = get_map();
+        assert_eq!(3, count(&map, Progress::Complete));
+    }
+
+    #[test]
+    fn count_equals_for() {
+        let map = get_map();
+        assert_eq!(
+            count_for(&map, Progress::Complete),
+            count(&map, Progress::Complete)
+        );
+    }
+
+    #[test]
+    fn count_stack_complete() {
+        let stack = get_map_stack();
+        assert_eq!(6, count_stack(&stack, Progress::Complete));
+    }
+
+    #[test]
+    fn count_stack_equals_for() {
+        let stack = get_map_stack();
+        assert_eq!(
+            count_stack_for(&stack, Progress::Complete),
+            count_stack(&stack, Progress::Complete)
+        );
+    }
+
+    fn get_map() -> HashMap<String, Progress> {
+        use Progress::*;
+
+        let mut map = HashMap::new();
+        map.insert(String::from("variables1"), Complete);
+        map.insert(String::from("functions1"), Complete);
+        map.insert(String::from("hashmap1"), Complete);
+        map.insert(String::from("arc1"), Some);
+        map.insert(String::from("as_ref_mut"), None);
+        map.insert(String::from("from_str"), None);
+
+        map
+    }
+
+    fn get_map_stack() -> Vec<HashMap<String, Progress>> {
+        use Progress::*;
+
+        let map = get_map();
+
+        let mut other = HashMap::new();
+        other.insert(String::from("variables2"), Complete);
+        other.insert(String::from("functions2"), Complete);
+        other.insert(String::from("if1"), Complete);
+        other.insert(String::from("from_into"), None);
+        other.insert(String::from("try_from_into"), None);
+
+        vec![map, other]
+    }
+}
diff --git a/info.toml b/info.toml
index f0fed934..646bb5a5 100644
--- a/info.toml
+++ b/info.toml
@@ -741,6 +741,21 @@ a mutable variable. Or, you might write code utilizing recursion
 and a match clause. In Rust you can take another functional
 approach, computing the factorial elegantly with ranges and iterators."""
 
+[[exercises]]
+name = "iterators5"
+path = "exercises/standard_library_types/iterators5.rs"
+mode = "test"
+hint = """
+The documentation for the std::iter::Iterator trait contains numerous methods
+that would be helpful here.
+
+Return 0 from count_stack to make the code compile in order to test count.
+
+The stack variable in count_stack is a slice of HashMaps. It needs to be
+converted into an iterator in order to use the iterator methods.
+
+The fold method can be useful in the count_stack function."""
+
 # THREADS
 
 [[exercises]]

From baf4ba175ba6eb92989e3dd54ecbec4bedc9a863 Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Thu, 11 Feb 2021 21:24:32 -0500
Subject: [PATCH 060/126] fix(iterators2): Moved errors out of tests.

Closes #359
---
 .../standard_library_types/iterators2.rs      | 38 ++++++++++++-------
 info.toml                                     | 19 +++++-----
 2 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs
index 84d14ae6..87b4eaa1 100644
--- a/exercises/standard_library_types/iterators2.rs
+++ b/exercises/standard_library_types/iterators2.rs
@@ -1,28 +1,41 @@
 // iterators2.rs
-// In this module, you'll learn some of the unique advantages that iterators can offer.
-// Step 1. Complete the `capitalize_first` function to pass the first two cases.
-// Step 2. Apply the `capitalize_first` function to a vector of strings.
-//         Ensure that it returns a vector of strings as well.
-// Step 3. Apply the `capitalize_first` function again to a list.
-//         Try to ensure it returns a single string.
+// In this exercise, you'll learn some of the unique advantages that iterators
+// can offer. Follow the steps to complete the exercise.
 // As always, there are hints if you execute `rustlings hint iterators2`!
 
 // I AM NOT DONE
 
+// Step 1.
+// Complete the `capitalize_first` function.
+// "hello" -> "Hello"
 pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => first.collect::<String>() + c.as_str(),
+        Some(first) => ???,
     }
 }
 
+// Step 2.
+// Apply the `capitalize_first` function to a slice of string slices.
+// Return a vector of strings.
+// ["hello", "world"] -> ["Hello", "World"]
+pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
+    vec![]
+}
+
+// Step 3.
+// Apply the `capitalize_first` function again to a slice of string slices.
+// Return a single string.
+// ["hello", " ", "world"] -> "Hello World"
+pub fn capitalize_words_string(words: &[&str]) -> String {
+    String::new()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    // Step 1.
-    // Tests that verify your `capitalize_first` function implementation
     #[test]
     fn test_success() {
         assert_eq!(capitalize_first("hello"), "Hello");
@@ -33,18 +46,15 @@ mod tests {
         assert_eq!(capitalize_first(""), "");
     }
 
-    // Step 2.
     #[test]
     fn test_iterate_string_vec() {
         let words = vec!["hello", "world"];
-        let capitalized_words: Vec<String> = // TODO
-        assert_eq!(capitalized_words, ["Hello", "World"]);
+        assert_eq!(capitalize_words_vector(&words), ["Hello", "World"]);
     }
 
     #[test]
     fn test_iterate_into_string() {
         let words = vec!["hello", " ", "world"];
-        let capitalized_words = // TODO
-        assert_eq!(capitalized_words, "Hello World");
+        assert_eq!(capitalize_words_string(&words), "Hello World");
     }
 }
diff --git a/info.toml b/info.toml
index f0fed934..5570b01c 100644
--- a/info.toml
+++ b/info.toml
@@ -704,21 +704,20 @@ path = "exercises/standard_library_types/iterators2.rs"
 mode = "test"
 hint = """
 Step 1
-You need to call something on `first` before it can be collected
-Currently its type is `char`. Have a look at the methods that are available on that type:
+The variable `first` is a `char`. It needs to be capitalized and added to the
+remaining characters in `c` in order to return the correct `String`.
+The remaining characters in `c` can be viewed as a string slice using the
+`as_str` method.
+The documentation for `char` contains many useful methods.
 https://doc.rust-lang.org/std/primitive.char.html
 
-
 Step 2
-First you'll need to turn the Vec into an iterator
-Then you'll need to apply your function unto each item in the vector
-P.s. Don't forget to collect() at the end!
-
+Create an iterator from the slice. Transform the iterated values by applying
+the `capitalize_first` function. Remember to collect the iterator.
 
 Step 3.
-This is very similar to the previous test. The only real change is that you will need to
-alter the type that collect is coerced into. For a bonus you could try doing this with a
-turbofish"""
+This is surprising similar to the previous solution. Collect is very powerful
+and very general. Rust just needs to know the desired type."""
 
 [[exercises]]
 name = "iterators3"

From c6712dfccd1a093e590ad22bbc4f49edc417dac0 Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Fri, 12 Feb 2021 15:36:53 -0500
Subject: [PATCH 061/126] fix(iterators3): Enabled iterators3.rs to run without
 commented out tests.

---
 .../standard_library_types/iterators3.rs      | 47 ++++++++++---------
 info.toml                                     | 12 +++--
 2 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/exercises/standard_library_types/iterators3.rs b/exercises/standard_library_types/iterators3.rs
index 353cea62..8c66c05b 100644
--- a/exercises/standard_library_types/iterators3.rs
+++ b/exercises/standard_library_types/iterators3.rs
@@ -1,11 +1,10 @@
 // iterators3.rs
 // This is a bigger exercise than most of the others! You can do it!
 // Here is your mission, should you choose to accept it:
-// 1. Complete the divide function to get the first four tests to pass
-// 2. Uncomment the last two tests and get them to pass by filling in
-//    values for `x` using `division_results`.
+// 1. Complete the divide function to get the first four tests to pass.
+// 2. Get the remaining tests to pass by completing the result_with_list and
+//    list_of_results functions.
 // Execute `rustlings hint iterators3` to get some hints!
-// Have fun :-)
 
 // I AM NOT DONE
 
@@ -21,16 +20,28 @@ pub struct NotDivisibleError {
     divisor: i32,
 }
 
-// This function should calculate `a` divided by `b` if `a` is
-// evenly divisible by b.
-// Otherwise, it should return a suitable error.
+// Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
+// Otherwise, return a suitable error.
 pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {}
 
+// Complete the function and return a value of the correct type so the test passes.
+// Desired output: Ok([1, 11, 1426, 3])
+fn result_with_list() -> () {
+    let numbers = vec![27, 297, 38502, 81];
+    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+}
+
+// Complete the function and return a value of the correct type so the test passes.
+// Desired output: [Ok(1), Ok(11), Ok(1426), Ok(3)]
+fn list_of_results() -> () {
+    let numbers = vec![27, 297, 38502, 81];
+    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    // Tests that verify your `divide` function implementation
     #[test]
     fn test_success() {
         assert_eq!(divide(81, 9), Ok(9));
@@ -57,22 +68,16 @@ mod tests {
         assert_eq!(divide(0, 81), Ok(0));
     }
 
-    // Iterator exercises using your `divide` function
-    /*
     #[test]
-    fn result_with_list() {
-        let numbers = vec![27, 297, 38502, 81];
-        let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
-        assert_eq!(format!("{:?}", x), "Ok([1, 11, 1426, 3])");
+    fn test_result_with_list() {
+        assert_eq!(format!("{:?}", result_with_list()), "Ok([1, 11, 1426, 3])");
     }
 
     #[test]
-    fn list_of_results() {
-        let numbers = vec![27, 297, 38502, 81];
-        let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
-        assert_eq!(format!("{:?}", x), "[Ok(1), Ok(11), Ok(1426), Ok(3)]");
+    fn test_list_of_results() {
+        assert_eq!(
+            format!("{:?}", list_of_results()),
+            "[Ok(1), Ok(11), Ok(1426), Ok(3)]"
+        );
     }
-    */
 }
diff --git a/info.toml b/info.toml
index f0fed934..73c5672c 100644
--- a/info.toml
+++ b/info.toml
@@ -725,11 +725,15 @@ name = "iterators3"
 path = "exercises/standard_library_types/iterators3.rs"
 mode = "test"
 hint = """
-Minor hint: In each of the two cases in the match in main, you can create x with either
-a 'turbofish' or by hinting the type of x to the compiler. You may try both.
+The divide function needs to return the correct error when even division is not
+possible.
 
-Major hint: Have a look at the Iter trait and at the explanation of its collect function.
-Especially the part about Result is interesting."""
+The division_results variable needs to be collected into a collection type.
+
+The result_with_list function needs to return a single Result where the success
+case is a vector of integers and the failure case is a DivisionError.
+
+The list_of_results function needs to return a vector of results."""
 
 [[exercises]]
 name = "iterators4"

From 5f7c89f85db1f33da01911eaa479c3a2d4721678 Mon Sep 17 00:00:00 2001
From: Jirka Kremser <535866+jkremser@users.noreply.github.com>
Date: Sun, 21 Feb 2021 21:50:17 +0100
Subject: [PATCH 062/126] fix(from_str): Correct typos

typos in the comments
---
 exercises/conversions/from_str.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/exercises/conversions/from_str.rs b/exercises/conversions/from_str.rs
index 558a9033..41fccd7e 100644
--- a/exercises/conversions/from_str.rs
+++ b/exercises/conversions/from_str.rs
@@ -13,13 +13,13 @@ struct Person {
 // I AM NOT DONE
 
 // Steps:
-// 1. If the length of the provided string is 0 an error should be returned
+// 1. If the length of the provided string is 0, an error should be returned
 // 2. Split the given string on the commas present in it
-// 3. Only 2 elements should returned from the split, otherwise return an error
+// 3. Only 2 elements should be returned from the split, otherwise return an error
 // 4. Extract the first element from the split operation and use it as the name
 // 5. Extract the other element from the split operation and parse it into a `usize` as the age
-//    with something like `"4".parse::<usize>()`.
-// 5. If while extracting the name and the age something goes wrong an error should be returned
+//    with something like `"4".parse::<usize>()`
+// 5. If while extracting the name and the age something goes wrong, an error should be returned
 // If everything goes well, then return a Result of a Person object
 
 impl FromStr for Person {

From 91ee27f22bd3797a9db57e5fd430801c170c5db8 Mon Sep 17 00:00:00 2001
From: Larry Garfield <larry@garfieldtech.com>
Date: Wed, 24 Feb 2021 15:03:26 -0600
Subject: [PATCH 063/126] fix: Spelling error

---
 src/main.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index 50e4a386..569aa4ac 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -213,7 +213,7 @@ fn main() {
     if matches.subcommand_matches("watch").is_some() {
         if let Err(e) = watch(&exercises, verbose) {
             println!(
-                "Error: Could not watch your progess. Error message was {:?}.",
+                "Error: Could not watch your progress. Error message was {:?}.",
                 e
             );
             println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");

From 320de0d92184fc0c4467a8cb5ac4af3b8fdcde6e Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Thu, 25 Feb 2021 10:20:53 +0000
Subject: [PATCH 064/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 9e617eba..8f7feb76 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-76-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-77-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -255,6 +255,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/jbaber"><img src="https://avatars.githubusercontent.com/u/1908117?v=4?s=100" width="100px;" alt=""/><br /><sub><b>John Baber-Lucero</b></sub></a><br /><a href="#content-jbaber" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/tal-zvon"><img src="https://avatars.githubusercontent.com/u/3195851?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Tal</b></sub></a><br /><a href="#content-tal-zvon" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/apogeeoak"><img src="https://avatars.githubusercontent.com/u/59737221?v=4?s=100" width="100px;" alt=""/><br /><sub><b>apogeeoak</b></sub></a><br /><a href="#content-apogeeoak" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apogeeoak" title="Code">💻</a></td>
+    <td align="center"><a href="http://www.garfieldtech.com/"><img src="https://avatars.githubusercontent.com/u/254863?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Larry Garfield</b></sub></a><br /><a href="#content-Crell" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 797e6d45c04c1833cbe608ca0c9af648e5373e25 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Thu, 25 Feb 2021 10:20:54 +0000
Subject: [PATCH 065/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index c4e68a15..3c2a0bb3 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -711,6 +711,15 @@
         "content",
         "code"
       ]
+    },
+    {
+      "login": "Crell",
+      "name": "Larry Garfield",
+      "avatar_url": "https://avatars.githubusercontent.com/u/254863?v=4",
+      "profile": "http://www.garfieldtech.com/",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 833df0b8b3bcc03df50f76f3b9ed15c5ffc60870 Mon Sep 17 00:00:00 2001
From: circumspect <40770208+circumspect@users.noreply.github.com>
Date: Fri, 12 Mar 2021 14:26:57 +0000
Subject: [PATCH 066/126] chore: fix typo

Co-authored-by: Chenkail <40770208+Chenkail@users.noreply.github.com>
---
 src/exercise.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/exercise.rs b/src/exercise.rs
index 7afa230a..18e8d5ab 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -235,7 +235,7 @@ path = "{}.rs""#,
 
     // Check that the exercise looks to be solved using self.state()
     // This is not the best way to check since
-    // the user can just remove the "I AM NOT DONE" string fromm the file
+    // the user can just remove the "I AM NOT DONE" string from the file
     // without actually having solved anything.
     // The only other way to truly check this would to compile and run
     // the exercise; which would be both costly and counterintuitive

From 3f5abca21535537dfcef69adaf2b08df790e47fa Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 12 Mar 2021 15:28:03 +0100
Subject: [PATCH 067/126] docs: add circumspect as a contributor

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 3c2a0bb3..9aa0630a 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -720,6 +720,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "circumspect",
+      "name": "circumspect",
+      "avatar_url": "https://avatars.githubusercontent.com/u/40770208?v=4",
+      "profile": "https://github.com/circumspect",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index 8f7feb76..97790643 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-77-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-78-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -256,6 +256,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/tal-zvon"><img src="https://avatars.githubusercontent.com/u/3195851?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Tal</b></sub></a><br /><a href="#content-tal-zvon" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/apogeeoak"><img src="https://avatars.githubusercontent.com/u/59737221?v=4?s=100" width="100px;" alt=""/><br /><sub><b>apogeeoak</b></sub></a><br /><a href="#content-apogeeoak" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apogeeoak" title="Code">💻</a></td>
     <td align="center"><a href="http://www.garfieldtech.com/"><img src="https://avatars.githubusercontent.com/u/254863?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Larry Garfield</b></sub></a><br /><a href="#content-Crell" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/circumspect"><img src="https://avatars.githubusercontent.com/u/40770208?v=4?s=100" width="100px;" alt=""/><br /><sub><b>circumspect</b></sub></a><br /><a href="#content-circumspect" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 5157f568753737bab860831d13fe342dec27b242 Mon Sep 17 00:00:00 2001
From: Cyrus Wyett <34195737+cjwyett@users.noreply.github.com>
Date: Fri, 12 Mar 2021 14:38:28 +0000
Subject: [PATCH 068/126] chore: fix typo

is however some --> are however some
---
 info.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/info.toml b/info.toml
index f0fed934..b37306c3 100644
--- a/info.toml
+++ b/info.toml
@@ -295,7 +295,7 @@ path = "exercises/structs/structs2.rs"
 mode = "test"
 hint = """
 Creating instances of structs is easy, all you need to do is assign some values to its fields.
-There is however some shortcuts that can be taken when instantiating structs.
+There are however some shortcuts that can be taken when instantiating structs.
 Have a look in The Book, to find out more: https://doc.rust-lang.org/stable/book/ch05-01-defining-structs.html#creating-instances-from-other-instances-with-struct-update-syntax"""
 
 [[exercises]]

From 815edb7003c58f60c6baecb7d91cd72614be7ad6 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 12 Mar 2021 15:39:40 +0100
Subject: [PATCH 069/126] docs: add cjwyett as a contributor (#666)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 9aa0630a..4eab3c6b 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -729,6 +729,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "cjwyett",
+      "name": "Cyrus Wyett",
+      "avatar_url": "https://avatars.githubusercontent.com/u/34195737?v=4",
+      "profile": "https://github.com/cjwyett",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index 97790643..ca99796f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-78-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-79-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -257,6 +257,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/apogeeoak"><img src="https://avatars.githubusercontent.com/u/59737221?v=4?s=100" width="100px;" alt=""/><br /><sub><b>apogeeoak</b></sub></a><br /><a href="#content-apogeeoak" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apogeeoak" title="Code">💻</a></td>
     <td align="center"><a href="http://www.garfieldtech.com/"><img src="https://avatars.githubusercontent.com/u/254863?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Larry Garfield</b></sub></a><br /><a href="#content-Crell" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/circumspect"><img src="https://avatars.githubusercontent.com/u/40770208?v=4?s=100" width="100px;" alt=""/><br /><sub><b>circumspect</b></sub></a><br /><a href="#content-circumspect" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/cjwyett"><img src="https://avatars.githubusercontent.com/u/34195737?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Cyrus Wyett</b></sub></a><br /><a href="#content-cjwyett" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 05a753fe6333d36dbee5f68c21dec04eacdc75df Mon Sep 17 00:00:00 2001
From: cadolphs <clemens.adolphs@gmail.com>
Date: Fri, 12 Mar 2021 09:36:35 -0800
Subject: [PATCH 070/126] fix: add check to prevent naive implementation of
 is_international

* fix(structs3): Add check to prevent naive implementation

* chore(structs3): Add a missed newline after the test I added
---
 exercises/structs/structs3.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/exercises/structs/structs3.rs b/exercises/structs/structs3.rs
index 06fcaf29..f18cc925 100644
--- a/exercises/structs/structs3.rs
+++ b/exercises/structs/structs3.rs
@@ -57,6 +57,16 @@ mod tests {
         assert!(package.is_international());
     }
 
+    #[test]
+    fn create_local_package() {
+        let sender_country = String::from("Canada");
+        let recipient_country = sender_country.clone();
+
+        let package = Package::new(sender_country, recipient_country, 1200);
+
+        assert!(!package.is_international());
+    }
+
     #[test]
     fn calculate_transport_fees() {
         let sender_country = String::from("Spain");

From 04dbf03ace1bc7f23f5f98bb701cba8505954c39 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Fri, 12 Mar 2021 18:37:58 +0100
Subject: [PATCH 071/126] docs: add cadolphs as a contributor (#667)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 4eab3c6b..45ea4b75 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -738,6 +738,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "cadolphs",
+      "name": "cadolphs",
+      "avatar_url": "https://avatars.githubusercontent.com/u/13894820?v=4",
+      "profile": "https://github.com/cadolphs",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index ca99796f..b958fae6 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-79-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-80-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -258,6 +258,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="http://www.garfieldtech.com/"><img src="https://avatars.githubusercontent.com/u/254863?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Larry Garfield</b></sub></a><br /><a href="#content-Crell" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/circumspect"><img src="https://avatars.githubusercontent.com/u/40770208?v=4?s=100" width="100px;" alt=""/><br /><sub><b>circumspect</b></sub></a><br /><a href="#content-circumspect" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/cjwyett"><img src="https://avatars.githubusercontent.com/u/34195737?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Cyrus Wyett</b></sub></a><br /><a href="#content-cjwyett" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/cadolphs"><img src="https://avatars.githubusercontent.com/u/13894820?v=4?s=100" width="100px;" alt=""/><br /><sub><b>cadolphs</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=cadolphs" title="Code">💻</a></td>
   </tr>
 </table>
 

From 96c56ab08a30835e9f4d2b6b83b75a0060726fbd Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Fri, 12 Mar 2021 14:04:29 -0500
Subject: [PATCH 072/126] chore: changed errors3 mode from test to compile

---
 info.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/info.toml b/info.toml
index b37306c3..2068750a 100644
--- a/info.toml
+++ b/info.toml
@@ -470,7 +470,7 @@ and give it a try!"""
 [[exercises]]
 name = "errors3"
 path = "exercises/error_handling/errors3.rs"
-mode = "test"
+mode = "compile"
 hint = """
 If other functions can return a `Result`, why shouldn't `main`?"""
 
@@ -694,7 +694,7 @@ Step 2 & step 2.1:
 Very similar to the lines above and below. You've got this!
 Step 3:
 An iterator goes through all elements in a collection, but what if we've run out of
-elements? What should we expect here? If you're stuck, take a look at 
+elements? What should we expect here? If you're stuck, take a look at
 https://doc.rust-lang.org/std/iter/trait.Iterator.html for some ideas.
 """
 

From 9f3e8c2dde645e5264c2d2200e68842b5f47bfa3 Mon Sep 17 00:00:00 2001
From: Darius Wiles <github@dariuswiles.com>
Date: Sat, 13 Mar 2021 03:14:02 -0800
Subject: [PATCH 073/126] fix(structs3): reword heading comment (#664)

---
 exercises/structs/structs3.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/exercises/structs/structs3.rs b/exercises/structs/structs3.rs
index f18cc925..8d8b4710 100644
--- a/exercises/structs/structs3.rs
+++ b/exercises/structs/structs3.rs
@@ -1,7 +1,8 @@
 // structs3.rs
-// Structs contain more than simply some data, they can also have logic, in this
-// exercise we have defined the Package struct and we want to test some logic attached to it,
-// make the code compile and the tests pass! If you have issues execute `rustlings hint structs3`
+// Structs contain data, but can also have logic. In this exercise we have
+// defined the Package struct and we want to test some logic attached to it.
+// Make the code compile and the tests pass!
+// If you have issues execute `rustlings hint structs3`
 
 // I AM NOT DONE
 

From ebdb66c7bfb6d687a14cc511a559a222e6fc5de4 Mon Sep 17 00:00:00 2001
From: Darius Wiles <github@dariuswiles.com>
Date: Sat, 13 Mar 2021 03:14:44 -0800
Subject: [PATCH 074/126] fix(structs2): correct grammar in hint (#663)


From 3bce2ef8d6a613f6601328b3679ec18256cefec9 Mon Sep 17 00:00:00 2001
From: Pascal H <hpwxf@haveneer.com>
Date: Mon, 15 Mar 2021 09:14:12 +0100
Subject: [PATCH 075/126] chore: clarify collections documentation

C++ `map` is more like BTreeMap.

`unordered_map` in C++(11) is the equivalent of `HashMap` in Rust.
(+ additional like for references).
---
 exercises/collections/README.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/exercises/collections/README.md b/exercises/collections/README.md
index 9ded29a0..af87863b 100644
--- a/exercises/collections/README.md
+++ b/exercises/collections/README.md
@@ -14,7 +14,7 @@ structures that are used very often in Rust programs:
 * A *vector* allows you to store a variable number of values next to
   each other.
 * A *hash map* allows you to associate a value with a particular key.
-  You may also know this by the names *map* in C++, *dictionary* in
-  Python or an *associative array* in other languages.
+  You may also know this by the names [*unordered map* in C++](https://en.cppreference.com/w/cpp/container/unordered_map), 
+  [*dictionary* in Python](https://docs.python.org/3/tutorial/datastructures.html#dictionaries) or an *associative array* in other languages.
 
 [Rust book chapter](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)

From be9510539e84c869362f6cd3fa6f791d3e02a821 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 15 Mar 2021 09:14:41 +0100
Subject: [PATCH 076/126] docs: add hpwxf as a contributor (#671)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 5 ++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 45ea4b75..5239b29c 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -747,6 +747,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "hpwxf",
+      "name": "Pascal H.",
+      "avatar_url": "https://avatars.githubusercontent.com/u/26146722?v=4",
+      "profile": "https://www.haveneer.com",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index b958fae6..85bba46d 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-80-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-81-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -260,6 +260,9 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/cjwyett"><img src="https://avatars.githubusercontent.com/u/34195737?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Cyrus Wyett</b></sub></a><br /><a href="#content-cjwyett" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/cadolphs"><img src="https://avatars.githubusercontent.com/u/13894820?v=4?s=100" width="100px;" alt=""/><br /><sub><b>cadolphs</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=cadolphs" title="Code">💻</a></td>
   </tr>
+  <tr>
+    <td align="center"><a href="https://www.haveneer.com"><img src="https://avatars.githubusercontent.com/u/26146722?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pascal H.</b></sub></a><br /><a href="#content-hpwxf" title="Content">🖋</a></td>
+  </tr>
 </table>
 
 <!-- markdownlint-restore -->

From 0d894e6ff739943901e1ae8c904582e5c2f843bd Mon Sep 17 00:00:00 2001
From: Pascal H <hpwxf@haveneer.com>
Date: Tue, 16 Mar 2021 10:14:25 +0100
Subject: [PATCH 077/126] fix(quiz3): Force an answer to Q2 (#672)

Add also an example of unimplemented!() macro.
---
 exercises/quiz3.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/exercises/quiz3.rs b/exercises/quiz3.rs
index a0cd3712..fae0eedb 100644
--- a/exercises/quiz3.rs
+++ b/exercises/quiz3.rs
@@ -24,6 +24,7 @@ mod tests {
 
     #[test]
     fn returns_twice_of_negative_numbers() {
-        // TODO write an assert for `times_two(-4)`
+        // TODO replace unimplemented!() with an assert for `times_two(-4)`
+        unimplemented!()
     }
 }

From bef39b125961310b34b34871e480a82e82af4678 Mon Sep 17 00:00:00 2001
From: Mickael Fortunato <morsi.morsicus@gmail.com>
Date: Thu, 18 Mar 2021 18:39:22 +0100
Subject: [PATCH 078/126] fix(collections): Naming exercises for vectors and
 hashmap

---
 exercises/collections/vec2.rs | 7 +------
 info.toml                     | 8 ++++----
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/exercises/collections/vec2.rs b/exercises/collections/vec2.rs
index ec6cfc00..08b6bbf5 100644
--- a/exercises/collections/vec2.rs
+++ b/exercises/collections/vec2.rs
@@ -28,11 +28,6 @@ mod tests {
         let v: Vec<i32> = (1..).filter(|x| x % 2 == 0).take(5).collect();
         let ans = vec_loop(v.clone());
 
-        assert_eq!(
-            ans,
-            v.iter()
-                .map(|x| x * 2)
-                .collect::<Vec<i32>>()
-        );
+        assert_eq!(ans, v.iter().map(|x| x * 2).collect::<Vec<i32>>());
     }
 }
diff --git a/info.toml b/info.toml
index 2068750a..baae76af 100644
--- a/info.toml
+++ b/info.toml
@@ -359,7 +359,7 @@ each constant."""
 # COLLECTIONS
 
 [[exercises]]
-name = "collections1"
+name = "vec1"
 path = "exercises/collections/vec1.rs"
 mode = "test"
 hint = """
@@ -373,7 +373,7 @@ of the Rust book to learn more.
 """
 
 [[exercises]]
-name = "collections2"
+name = "vec2"
 path = "exercises/collections/vec2.rs"
 mode = "test"
 hint = """
@@ -383,7 +383,7 @@ Hint 2: Check the suggestion from the compiler error ;)
 """
 
 [[exercises]]
-name = "collections3"
+name = "hashmap1"
 path = "exercises/collections/hashmap1.rs"
 mode = "test"
 hint = """
@@ -394,7 +394,7 @@ Hint 2: Number of fruits should be at least 5. And you have to put
 """
 
 [[exercises]]
-name = "collections4"
+name = "hashmap2"
 path = "exercises/collections/hashmap2.rs"
 mode = "test"
 hint = """

From ab9995e76e10fb1159f9ca1f378e3e11838dc5bc Mon Sep 17 00:00:00 2001
From: Mickael Fortunato <morsi.morsicus@gmail.com>
Date: Thu, 18 Mar 2021 18:45:01 +0100
Subject: [PATCH 079/126] doc: Update collections exercises instruction to
 match the standard naming

---
 exercises/collections/hashmap1.rs | 6 ++----
 exercises/collections/hashmap2.rs | 6 ++----
 exercises/collections/vec1.rs     | 2 +-
 exercises/collections/vec2.rs     | 2 +-
 4 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/exercises/collections/hashmap1.rs b/exercises/collections/hashmap1.rs
index b1dc0bbd..64b5a7f3 100644
--- a/exercises/collections/hashmap1.rs
+++ b/exercises/collections/hashmap1.rs
@@ -8,7 +8,7 @@
 //
 // Make me compile and pass the tests!
 //
-// Execute the command `rustlings hint collections3` if you need
+// Execute the command `rustlings hint hashmap1` if you need
 // hints.
 
 // I AM NOT DONE
@@ -39,8 +39,6 @@ mod tests {
     #[test]
     fn at_least_five_fruits() {
         let basket = fruit_basket();
-        assert!(basket
-            .values()
-            .sum::<u32>() >= 5);
+        assert!(basket.values().sum::<u32>() >= 5);
     }
 }
diff --git a/exercises/collections/hashmap2.rs b/exercises/collections/hashmap2.rs
index 7e25be7c..f865fe1c 100644
--- a/exercises/collections/hashmap2.rs
+++ b/exercises/collections/hashmap2.rs
@@ -9,7 +9,7 @@
 //
 // Make me pass the tests!
 //
-// Execute the command `rustlings hint collections4` if you need
+// Execute the command `rustlings hint hashmap2` if you need
 // hints.
 
 // I AM NOT DONE
@@ -75,9 +75,7 @@ mod tests {
     fn greater_than_eleven_fruits() {
         let mut basket = get_fruit_basket();
         fruit_basket(&mut basket);
-        let count = basket
-            .values()
-            .sum::<u32>();
+        let count = basket.values().sum::<u32>();
         assert!(count > 11);
     }
 }
diff --git a/exercises/collections/vec1.rs b/exercises/collections/vec1.rs
index f6bc837c..b144fb94 100644
--- a/exercises/collections/vec1.rs
+++ b/exercises/collections/vec1.rs
@@ -2,7 +2,7 @@
 // Your task is to create a `Vec` which holds the exact same elements
 // as in the array `a`.
 // Make me compile and pass the test!
-// Execute the command `rustlings hint collections1` if you need hints.
+// Execute the command `rustlings hint vec1` if you need hints.
 
 // I AM NOT DONE
 
diff --git a/exercises/collections/vec2.rs b/exercises/collections/vec2.rs
index 08b6bbf5..6595e401 100644
--- a/exercises/collections/vec2.rs
+++ b/exercises/collections/vec2.rs
@@ -4,7 +4,7 @@
 //
 // Make me pass the test!
 //
-// Execute the command `rustlings hint collections2` if you need
+// Execute the command `rustlings hint vec2` if you need
 // hints.
 
 // I AM NOT DONE

From 8d62a9963708dbecd9312e8bcc4b47049c72d155 Mon Sep 17 00:00:00 2001
From: Matt Lebl <lebl.matt@gmail.com>
Date: Fri, 19 Mar 2021 02:16:07 -0700
Subject: [PATCH 080/126] feat: Replace emojis when NO_EMOJI env variable
 present

---
 src/exercise.rs |  7 ++++++-
 src/ui.rs       | 44 ++++++++++++++++++++++++++++++++++----------
 src/verify.rs   | 15 +++++++++++++--
 3 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/src/exercise.rs b/src/exercise.rs
index 18e8d5ab..2c5d835e 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -1,3 +1,4 @@
+use std::env;
 use regex::Regex;
 use serde::Deserialize;
 use std::fmt::{self, Display, Formatter};
@@ -126,8 +127,12 @@ name = "{}"
 path = "{}.rs""#,
                     self.name, self.name, self.name
                 );
+                let cargo_toml_error_msg = match env::var("NO_EMOJI").is_ok() {
+                    true => "Failed to write Clippy Cargo.toml file.",
+                    false => "Failed to write 📎 Clippy 📎 Cargo.toml file."
+                };
                 fs::write(CLIPPY_CARGO_TOML_PATH, cargo_toml)
-                    .expect("Failed to write 📎 Clippy 📎 Cargo.toml file.");
+                    .expect(cargo_toml_error_msg);
                 // To support the ability to run the clipy exercises, build
                 // an executable, in addition to running clippy. With a
                 // compilation failure, this would silently fail. But we expect
diff --git a/src/ui.rs b/src/ui.rs
index 38cbaa40..7ab87546 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -1,23 +1,47 @@
 macro_rules! warn {
     ($fmt:literal, $ex:expr) => {{
+        use std::env;
         use console::{style, Emoji};
         let formatstr = format!($fmt, $ex);
-        println!(
-            "{} {}",
-            style(Emoji("⚠️ ", "!")).red(),
-            style(formatstr).red()
-        );
+        match env::var("NO_EMOJI").is_ok() {
+            true => {
+                println!(
+                    "{} {}",
+                    style("!").red(),
+                    style(formatstr).red()
+                );
+            },
+            false => {
+                println!(
+                    "{} {}",
+                    style(Emoji("⚠️ ", "!")).red(),
+                    style(formatstr).red()
+                );
+            }
+        }
     }};
 }
 
 macro_rules! success {
     ($fmt:literal, $ex:expr) => {{
+        use std::env;
         use console::{style, Emoji};
         let formatstr = format!($fmt, $ex);
-        println!(
-            "{} {}",
-            style(Emoji("✅", "✓")).green(),
-            style(formatstr).green()
-        );
+        match env::var("NO_EMOJI").is_ok() {
+            true => {
+                println!(
+                    "{} {}",
+                    style("✓").green(),
+                    style(formatstr).green()
+                );
+            },
+            false => {
+                println!(
+                    "{} {}",
+                    style(Emoji("✅", "✓")).green(),
+                    style(formatstr).green()
+                );
+            }
+        }
     }};
 }
diff --git a/src/verify.rs b/src/verify.rs
index 00e45c8c..04acfc68 100644
--- a/src/verify.rs
+++ b/src/verify.rs
@@ -1,3 +1,4 @@
+use std::env;
 use crate::exercise::{CompiledExercise, Exercise, Mode, State};
 use console::style;
 use indicatif::ProgressBar;
@@ -137,14 +138,24 @@ fn prompt_for_completion(exercise: &Exercise, prompt_output: Option<String>) ->
         State::Pending(context) => context,
     };
 
+    let no_emoji = env::var("NO_EMOJI").is_ok();
+
+    let clippy_success_msg = match no_emoji {
+        true => "The code is compiling, and Clippy is happy!",
+        false => "The code is compiling, and 📎 Clippy 📎 is happy!"
+    };
+
     let success_msg = match exercise.mode {
         Mode::Compile => "The code is compiling!",
         Mode::Test => "The code is compiling, and the tests pass!",
-        Mode::Clippy => "The code is compiling, and 📎 Clippy 📎 is happy!",
+        Mode::Clippy => clippy_success_msg,
     };
 
     println!();
-    println!("🎉 🎉  {} 🎉 🎉", success_msg);
+    match no_emoji {
+        true => println!("~*~ {} ~*~", success_msg),
+        false => println!("🎉 🎉  {} 🎉 🎉", success_msg)
+    };
     println!();
 
     if let Some(output) = prompt_output {

From 01e7f27aa6ab9ba868f3997c1e5f5d3aa0bac57a Mon Sep 17 00:00:00 2001
From: Matt Lebl <lebl.matt@gmail.com>
Date: Sat, 20 Mar 2021 11:52:57 -0700
Subject: [PATCH 081/126] refactor: change from match to if for NO_EMOJI

---
 src/exercise.rs |  7 ++++---
 src/ui.rs       | 54 ++++++++++++++++++++++---------------------------
 src/verify.rs   | 16 ++++++++-------
 3 files changed, 37 insertions(+), 40 deletions(-)

diff --git a/src/exercise.rs b/src/exercise.rs
index 2c5d835e..3d2e38d1 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -127,9 +127,10 @@ name = "{}"
 path = "{}.rs""#,
                     self.name, self.name, self.name
                 );
-                let cargo_toml_error_msg = match env::var("NO_EMOJI").is_ok() {
-                    true => "Failed to write Clippy Cargo.toml file.",
-                    false => "Failed to write 📎 Clippy 📎 Cargo.toml file."
+                let cargo_toml_error_msg = if env::var("NO_EMOJI").is_ok() {
+                    "Failed to write Clippy Cargo.toml file."
+                } else {
+                    "Failed to write 📎 Clippy 📎 Cargo.toml file."
                 };
                 fs::write(CLIPPY_CARGO_TOML_PATH, cargo_toml)
                     .expect(cargo_toml_error_msg);
diff --git a/src/ui.rs b/src/ui.rs
index 7ab87546..cb073372 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -3,21 +3,18 @@ macro_rules! warn {
         use std::env;
         use console::{style, Emoji};
         let formatstr = format!($fmt, $ex);
-        match env::var("NO_EMOJI").is_ok() {
-            true => {
-                println!(
-                    "{} {}",
-                    style("!").red(),
-                    style(formatstr).red()
-                );
-            },
-            false => {
-                println!(
-                    "{} {}",
-                    style(Emoji("⚠️ ", "!")).red(),
-                    style(formatstr).red()
-                );
-            }
+        if env::var("NO_EMOJI").is_ok() {
+            println!(
+                "{} {}",
+                style("!").red(),
+                style(formatstr).red()
+            );
+        } else {
+            println!(
+                "{} {}",
+                style(Emoji("⚠️ ", "!")).red(),
+                style(formatstr).red()
+            );
         }
     }};
 }
@@ -27,21 +24,18 @@ macro_rules! success {
         use std::env;
         use console::{style, Emoji};
         let formatstr = format!($fmt, $ex);
-        match env::var("NO_EMOJI").is_ok() {
-            true => {
-                println!(
-                    "{} {}",
-                    style("✓").green(),
-                    style(formatstr).green()
-                );
-            },
-            false => {
-                println!(
-                    "{} {}",
-                    style(Emoji("✅", "✓")).green(),
-                    style(formatstr).green()
-                );
-            }
+        if env::var("NO_EMOJI").is_ok() {
+            println!(
+                "{} {}",
+                style("✓").green(),
+                style(formatstr).green()
+            );
+        } else {
+            println!(
+                "{} {}",
+                style(Emoji("✅", "✓")).green(),
+                style(formatstr).green()
+            );
         }
     }};
 }
diff --git a/src/verify.rs b/src/verify.rs
index 04acfc68..7a0e9ccd 100644
--- a/src/verify.rs
+++ b/src/verify.rs
@@ -140,9 +140,10 @@ fn prompt_for_completion(exercise: &Exercise, prompt_output: Option<String>) ->
 
     let no_emoji = env::var("NO_EMOJI").is_ok();
 
-    let clippy_success_msg = match no_emoji {
-        true => "The code is compiling, and Clippy is happy!",
-        false => "The code is compiling, and 📎 Clippy 📎 is happy!"
+    let clippy_success_msg = if no_emoji {
+        "The code is compiling, and Clippy is happy!"
+    } else {
+        "The code is compiling, and 📎 Clippy 📎 is happy!"
     };
 
     let success_msg = match exercise.mode {
@@ -152,10 +153,11 @@ fn prompt_for_completion(exercise: &Exercise, prompt_output: Option<String>) ->
     };
 
     println!();
-    match no_emoji {
-        true => println!("~*~ {} ~*~", success_msg),
-        false => println!("🎉 🎉  {} 🎉 🎉", success_msg)
-    };
+    if no_emoji {
+        println!("~*~ {} ~*~", success_msg)
+    } else {
+        println!("🎉 🎉  {} 🎉 🎉", success_msg)
+    }
     println!();
 
     if let Some(output) = prompt_output {

From 3df094713f4546745d4a9ea75cd75cba62473067 Mon Sep 17 00:00:00 2001
From: Rod Elias <rodiney@gmail.com>
Date: Sat, 20 Mar 2021 17:12:49 -0300
Subject: [PATCH 082/126] chore: capitalize `c` letter

By capitalizing the `c` letter it makes clear that we're talking about the C programming language.
---
 exercises/structs/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/structs/README.md b/exercises/structs/README.md
index d2d7dc24..72e0061b 100644
--- a/exercises/structs/README.md
+++ b/exercises/structs/README.md
@@ -1,6 +1,6 @@
 ### Structs
 
-Rust has three struct types: a classic c struct, a tuple struct, and a unit struct.
+Rust has three struct types: a classic C struct, a tuple struct, and a unit struct.
 
 #### Book Sections
 

From 550c4293ed269a7d888c384076ba247662af58c3 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sat, 20 Mar 2021 21:13:35 +0100
Subject: [PATCH 083/126] docs: add chapeupreto as a contributor (#678)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>
---
 .all-contributorsrc | 9 +++++++++
 README.md           | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 5239b29c..ccce9476 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -756,6 +756,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "chapeupreto",
+      "name": "Rod Elias",
+      "avatar_url": "https://avatars.githubusercontent.com/u/834048?v=4",
+      "profile": "https://twitter.com/chapeupreto",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/README.md b/README.md
index 85bba46d..995b4258 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-81-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-82-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -262,6 +262,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   </tr>
   <tr>
     <td align="center"><a href="https://www.haveneer.com"><img src="https://avatars.githubusercontent.com/u/26146722?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pascal H.</b></sub></a><br /><a href="#content-hpwxf" title="Content">🖋</a></td>
+    <td align="center"><a href="https://twitter.com/chapeupreto"><img src="https://avatars.githubusercontent.com/u/834048?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rod Elias</b></sub></a><br /><a href="#content-chapeupreto" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 8dc587b01ab2e49a06308de29541330ff83dc371 Mon Sep 17 00:00:00 2001
From: marisa <mokou@fastmail.com>
Date: Sun, 21 Mar 2021 16:34:21 +0100
Subject: [PATCH 084/126] chore: Update install URLs

---
 README.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 995b4258..5871e3dc 100644
--- a/README.md
+++ b/README.md
@@ -24,9 +24,9 @@ You will need to have Rust installed. You can get it by visiting https://rustup.
 Just run:
 
 ```bash
-curl -L https://git.io/rustlings | bash
+curl -L https://git.io/install-rustlings | bash
 # Or if you want it to be installed to a different path:
-curl -L https://git.io/rustlings | bash -s mypath/
+curl -L https://git.io/install-rustlings | bash -s mypath/
 ```
 
 This will install Rustlings and give you access to the `rustlings` command. Run it to get started!
@@ -42,7 +42,7 @@ Set-ExecutionPolicy RemoteSigned
 Then, you can run:
 
 ```ps
-Start-BitsTransfer -Source https://git.io/rustlings-win -Destination $env:TMP/install_rustlings.ps1; Unblock-File $env:TMP/install_rustlings.ps1; Invoke-Expression $env:TMP/install_rustlings.ps1
+Start-BitsTransfer -Source https://git.io/install-rustlings-win -Destination $env:TMP/install_rustlings.ps1; Unblock-File $env:TMP/install_rustlings.ps1; Invoke-Expression $env:TMP/install_rustlings.ps1
 ```
 
 To install Rustlings. Same as on MacOS/Linux, you will have access to the `rustlings` command after it.

From c163011cc0e3b0d9eaae7ae51aadba1cf9a2226e Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 22 Mar 2021 12:37:01 +0000
Subject: [PATCH 085/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 5871e3dc..75e298fb 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-82-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-83-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -263,6 +263,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://www.haveneer.com"><img src="https://avatars.githubusercontent.com/u/26146722?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pascal H.</b></sub></a><br /><a href="#content-hpwxf" title="Content">🖋</a></td>
     <td align="center"><a href="https://twitter.com/chapeupreto"><img src="https://avatars.githubusercontent.com/u/834048?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rod Elias</b></sub></a><br /><a href="#content-chapeupreto" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/blerchy"><img src="https://avatars.githubusercontent.com/u/2555355?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Matt Lebl</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=blerchy" title="Code">💻</a></td>
   </tr>
 </table>
 

From 2a6e4dc8a65a1658f55edc5fe63854197839b358 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 22 Mar 2021 12:37:02 +0000
Subject: [PATCH 086/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index ccce9476..4726b643 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -765,6 +765,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "blerchy",
+      "name": "Matt Lebl",
+      "avatar_url": "https://avatars.githubusercontent.com/u/2555355?v=4",
+      "profile": "https://github.com/blerchy",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From a02b27975018f69c51147f5f8d9638a5f4e26811 Mon Sep 17 00:00:00 2001
From: marisa <mokou@fastmail.com>
Date: Tue, 23 Mar 2021 09:10:40 +0100
Subject: [PATCH 087/126] chore: Provide a working Windows installation link

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 75e298fb..b453bf41 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ Set-ExecutionPolicy RemoteSigned
 Then, you can run:
 
 ```ps
-Start-BitsTransfer -Source https://git.io/install-rustlings-win -Destination $env:TMP/install_rustlings.ps1; Unblock-File $env:TMP/install_rustlings.ps1; Invoke-Expression $env:TMP/install_rustlings.ps1
+Start-BitsTransfer -Source https://git.io/JTL5v -Destination $env:TMP/install_rustlings.ps1; Unblock-File $env:TMP/install_rustlings.ps1; Invoke-Expression $env:TMP/install_rustlings.ps1
 ```
 
 To install Rustlings. Same as on MacOS/Linux, you will have access to the `rustlings` command after it.

From a6509cc4d545d8825f01ddf7ee37823b372154dd Mon Sep 17 00:00:00 2001
From: Ignacio Le Fluk <flakolefluk@gmail.com>
Date: Sun, 4 Apr 2021 03:43:25 -0400
Subject: [PATCH 088/126] fix(functions3): improve function argument type
 (#687)

---
 exercises/functions/functions3.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/functions/functions3.rs b/exercises/functions/functions3.rs
index e3c1bf73..ed5f839f 100644
--- a/exercises/functions/functions3.rs
+++ b/exercises/functions/functions3.rs
@@ -7,7 +7,7 @@ fn main() {
     call_me();
 }
 
-fn call_me(num: i32) {
+fn call_me(num: u32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

From aec2c65c632c94793d23fbb1fb826dd78e59ffdf Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sun, 4 Apr 2021 07:43:50 +0000
Subject: [PATCH 089/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index b453bf41..479a307c 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-83-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-84-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -264,6 +264,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://www.haveneer.com"><img src="https://avatars.githubusercontent.com/u/26146722?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pascal H.</b></sub></a><br /><a href="#content-hpwxf" title="Content">🖋</a></td>
     <td align="center"><a href="https://twitter.com/chapeupreto"><img src="https://avatars.githubusercontent.com/u/834048?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rod Elias</b></sub></a><br /><a href="#content-chapeupreto" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/blerchy"><img src="https://avatars.githubusercontent.com/u/2555355?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Matt Lebl</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=blerchy" title="Code">💻</a></td>
+    <td align="center"><a href="http://flakolefluk.dev"><img src="https://avatars.githubusercontent.com/u/11986564?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ignacio Le Fluk</b></sub></a><br /><a href="#content-flakolefluk" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 2193fff4bb5e6becee03b1e9c37ee5069e6c9138 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sun, 4 Apr 2021 07:43:51 +0000
Subject: [PATCH 090/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 4726b643..b0975cfe 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -774,6 +774,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "flakolefluk",
+      "name": "Ignacio Le Fluk",
+      "avatar_url": "https://avatars.githubusercontent.com/u/11986564?v=4",
+      "profile": "http://flakolefluk.dev",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 2e93a588e0abe8badb7eafafb9e7d073c2be5df8 Mon Sep 17 00:00:00 2001
From: Taylor Yu <tlyu@mit.edu>
Date: Sun, 4 Apr 2021 00:04:03 -0500
Subject: [PATCH 091/126] fix: use trait objects for try_from_into

Use `Box<dyn error::Error>` to allow solutions to use `?` to propagate
errors.  In the tests, explicitly check `is_ok()` instead of trying to
force the error type to `String` (or other `PartialEq` type) using
`assert_eq!()`.
---
 exercises/conversions/try_from_into.rs | 40 ++++++++++++++------------
 1 file changed, 22 insertions(+), 18 deletions(-)

diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index e405c3f4..c0b5d986 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -3,6 +3,7 @@
 // instead of the target type itself.
 // You can read more about it at https://doc.rust-lang.org/std/convert/trait.TryFrom.html
 use std::convert::{TryFrom, TryInto};
+use std::error;
 
 #[derive(Debug, PartialEq)]
 struct Color {
@@ -24,19 +25,19 @@ struct Color {
 
 // Tuple implementation
 impl TryFrom<(i16, i16, i16)> for Color {
-    type Error = String;
+    type Error = Box<dyn error::Error>;
     fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
 }
 
 // Array implementation
 impl TryFrom<[i16; 3]> for Color {
-    type Error = String;
+    type Error = Box<dyn error::Error>;
     fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
 }
 
 // Slice implementation
 impl TryFrom<&[i16]> for Color {
-    type Error = String;
+    type Error = Box<dyn error::Error>;
     fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
 }
 
@@ -76,41 +77,43 @@ mod tests {
     }
     #[test]
     fn test_tuple_correct() {
-        let c: Result<Color, String> = (183, 65, 14).try_into();
+        let c: Result<Color, _> = (183, 65, 14).try_into();
+        assert!(c.is_ok());
         assert_eq!(
-            c,
-            Ok(Color {
+            c.unwrap(),
+            Color {
                 red: 183,
                 green: 65,
                 blue: 14
-            })
+            }
         );
     }
     #[test]
     fn test_array_out_of_range_positive() {
-        let c: Result<Color, String> = [1000, 10000, 256].try_into();
+        let c: Result<Color, _> = [1000, 10000, 256].try_into();
         assert!(c.is_err());
     }
     #[test]
     fn test_array_out_of_range_negative() {
-        let c: Result<Color, String> = [-10, -256, -1].try_into();
+        let c: Result<Color, _> = [-10, -256, -1].try_into();
         assert!(c.is_err());
     }
     #[test]
     fn test_array_sum() {
-        let c: Result<Color, String> = [-1, 255, 255].try_into();
+        let c: Result<Color, _> = [-1, 255, 255].try_into();
         assert!(c.is_err());
     }
     #[test]
     fn test_array_correct() {
-        let c: Result<Color, String> = [183, 65, 14].try_into();
+        let c: Result<Color, _> = [183, 65, 14].try_into();
+        assert!(c.is_ok());
         assert_eq!(
-            c,
-            Ok(Color {
+            c.unwrap(),
+            Color {
                 red: 183,
                 green: 65,
                 blue: 14
-            })
+            }
         );
     }
     #[test]
@@ -131,14 +134,15 @@ mod tests {
     #[test]
     fn test_slice_correct() {
         let v = vec![183, 65, 14];
-        let c: Result<Color, String> = Color::try_from(&v[..]);
+        let c: Result<Color, _> = Color::try_from(&v[..]);
+        assert!(c.is_ok());
         assert_eq!(
-            c,
-            Ok(Color {
+            c.unwrap(),
+            Color {
                 red: 183,
                 green: 65,
                 blue: 14
-            })
+            }
         );
     }
     #[test]

From c3e7b831786c9172ed8bd5d150f3c432f242fba9 Mon Sep 17 00:00:00 2001
From: Taylor Yu <tlyu@mit.edu>
Date: Sun, 4 Apr 2021 18:43:38 -0500
Subject: [PATCH 092/126] fix: use trait objects for from_str

Use `Box<dyn error::Error>` to allow solutions to use `?` to propagate
errors.
---
 exercises/conversions/from_str.rs | 3 ++-
 info.toml                         | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/exercises/conversions/from_str.rs b/exercises/conversions/from_str.rs
index 41fccd7e..4beebacd 100644
--- a/exercises/conversions/from_str.rs
+++ b/exercises/conversions/from_str.rs
@@ -2,6 +2,7 @@
 // Additionally, upon implementing FromStr, you can use the `parse` method
 // on strings to generate an object of the implementor type.
 // You can read more about it at https://doc.rust-lang.org/std/str/trait.FromStr.html
+use std::error;
 use std::str::FromStr;
 
 #[derive(Debug)]
@@ -23,7 +24,7 @@ struct Person {
 // If everything goes well, then return a Result of a Person object
 
 impl FromStr for Person {
-    type Err = String;
+    type Err = Box<dyn error::Error>;
     fn from_str(s: &str) -> Result<Person, Self::Err> {
     }
 }
diff --git a/info.toml b/info.toml
index 2068750a..4a1d3aa3 100644
--- a/info.toml
+++ b/info.toml
@@ -884,5 +884,5 @@ path = "exercises/conversions/from_str.rs"
 mode = "test"
 hint = """
 The implementation of FromStr should return an Ok with a Person object,
-or an Err with a string if the string is not valid.
+or an Err with an error if the string is not valid.
 This is almost like the `try_from_into` exercise."""

From 1ad20d94ff6982e66561d03727e52f04ffa8756b Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 5 Apr 2021 11:27:16 +0000
Subject: [PATCH 093/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 479a307c..6ffef489 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-84-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-85-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -265,6 +265,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://twitter.com/chapeupreto"><img src="https://avatars.githubusercontent.com/u/834048?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Rod Elias</b></sub></a><br /><a href="#content-chapeupreto" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/blerchy"><img src="https://avatars.githubusercontent.com/u/2555355?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Matt Lebl</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=blerchy" title="Code">💻</a></td>
     <td align="center"><a href="http://flakolefluk.dev"><img src="https://avatars.githubusercontent.com/u/11986564?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ignacio Le Fluk</b></sub></a><br /><a href="#content-flakolefluk" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/tlyu"><img src="https://avatars.githubusercontent.com/u/431873?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Taylor Yu</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=tlyu" title="Code">💻</a> <a href="#content-tlyu" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 1a6a725f882ac25b4ed12cd960fdc3aad9b80eb3 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Mon, 5 Apr 2021 11:27:17 +0000
Subject: [PATCH 094/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index b0975cfe..c7f10be4 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -783,6 +783,16 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "tlyu",
+      "name": "Taylor Yu",
+      "avatar_url": "https://avatars.githubusercontent.com/u/431873?v=4",
+      "profile": "https://github.com/tlyu",
+      "contributions": [
+        "code",
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From b790bafc02b6cbeab928a5ddeba30ed8b111a817 Mon Sep 17 00:00:00 2001
From: WowSuchRicky <wowsuchricky@gmail.com>
Date: Fri, 9 Apr 2021 14:08:02 -0700
Subject: [PATCH 095/126] Rename lichi to lychee in the fruit example

---
 exercises/collections/hashmap2.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/exercises/collections/hashmap2.rs b/exercises/collections/hashmap2.rs
index 7e25be7c..cacdf203 100644
--- a/exercises/collections/hashmap2.rs
+++ b/exercises/collections/hashmap2.rs
@@ -4,7 +4,7 @@
 // represents the name of the fruit and the value represents how many
 // of that particular fruit is in the basket. You have to put *MORE
 // THAN 11* fruits in the basket. Three types of fruits - Apple (4),
-// Mango (2) and Lichi (5) are already given in the basket. You are
+// Mango (2) and Lychee (5) are already given in the basket. You are
 // not allowed to insert any more of these fruits!
 //
 // Make me pass the tests!
@@ -21,7 +21,7 @@ enum Fruit {
     Apple,
     Banana,
     Mango,
-    Lichi,
+    Lychee,
     Pineapple,
 }
 
@@ -30,7 +30,7 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         Fruit::Apple,
         Fruit::Banana,
         Fruit::Mango,
-        Fruit::Lichi,
+        Fruit::Lychee,
         Fruit::Pineapple,
     ];
 
@@ -49,7 +49,7 @@ mod tests {
         let mut basket = HashMap::<Fruit, u32>::new();
         basket.insert(Fruit::Apple, 4);
         basket.insert(Fruit::Mango, 2);
-        basket.insert(Fruit::Lichi, 5);
+        basket.insert(Fruit::Lychee, 5);
 
         basket
     }
@@ -60,7 +60,7 @@ mod tests {
         fruit_basket(&mut basket);
         assert_eq!(*basket.get(&Fruit::Apple).unwrap(), 4);
         assert_eq!(*basket.get(&Fruit::Mango).unwrap(), 2);
-        assert_eq!(*basket.get(&Fruit::Lichi).unwrap(), 5);
+        assert_eq!(*basket.get(&Fruit::Lychee).unwrap(), 5);
     }
 
     #[test]

From c0e3daacaf6850811df5bc57fa43e0f249d5cfa4 Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Sun, 18 Apr 2021 15:37:41 +0200
Subject: [PATCH 096/126] feat(list): added progress info

Added a progress info at the bottom of the list for command: rustlings list

closes #705
---
 src/main.rs | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 569aa4ac..73647234 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -138,13 +138,19 @@ fn main() {
             println!("{:<17}\t{:<46}\t{:<7}", "Name", "Path", "Status");
         }
         let filters = list_m.value_of("filter").unwrap_or_default().to_lowercase();
+        let mut exercises_done: u16 = 0;
         exercises.iter().for_each(|e| {
             let fname = format!("{}", e.path.display());
             let filter_cond = filters
                 .split(',')
                 .filter(|f| !f.trim().is_empty())
                 .any(|f| e.name.contains(&f) || fname.contains(&f));
-            let status = if e.looks_done() { "Done" } else { "Pending" };
+            let status = if e.looks_done() {
+                exercises_done = exercises_done + 1;
+                "Done"
+            } else {
+                "Pending"
+            };
             let solve_cond = {
                 (e.looks_done() && list_m.is_present("solved"))
                     || (!e.looks_done() && list_m.is_present("unsolved"))
@@ -173,6 +179,13 @@ fn main() {
                 }
             }
         });
+        let percentage_progress = exercises_done as f32 / exercises.len() as f32;
+        println!(
+            "Progress: You completed {} / {} exercises ({:.2} %).",
+            exercises_done,
+            exercises.len(),
+            percentage_progress
+        );
         std::process::exit(0);
     }
 
@@ -314,7 +327,7 @@ fn watch(exercises: &[Exercise], verbose: bool) -> notify::Result<()> {
                             .chain(
                                 exercises
                                     .iter()
-                                    .filter(|e| !e.looks_done() && !filepath.ends_with(&e.path))
+                                    .filter(|e| !e.looks_done() && !filepath.ends_with(&e.path)),
                             );
                         clear_screen();
                         match verify(pending_exercises, verbose) {

From bd48544e25bb58f86fee1b1a5004e961996a3388 Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Sun, 18 Apr 2021 15:40:47 +0200
Subject: [PATCH 097/126] style: formatted files with rustfmt

---
 src/exercise.rs |  5 ++---
 src/ui.rs       | 16 ++++------------
 src/verify.rs   |  2 +-
 3 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/src/exercise.rs b/src/exercise.rs
index 3d2e38d1..e9d1c1c9 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -1,6 +1,6 @@
-use std::env;
 use regex::Regex;
 use serde::Deserialize;
+use std::env;
 use std::fmt::{self, Display, Formatter};
 use std::fs::{self, remove_file, File};
 use std::io::Read;
@@ -132,8 +132,7 @@ path = "{}.rs""#,
                 } else {
                     "Failed to write 📎 Clippy 📎 Cargo.toml file."
                 };
-                fs::write(CLIPPY_CARGO_TOML_PATH, cargo_toml)
-                    .expect(cargo_toml_error_msg);
+                fs::write(CLIPPY_CARGO_TOML_PATH, cargo_toml).expect(cargo_toml_error_msg);
                 // To support the ability to run the clipy exercises, build
                 // an executable, in addition to running clippy. With a
                 // compilation failure, this would silently fail. But we expect
diff --git a/src/ui.rs b/src/ui.rs
index cb073372..1ee46316 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -1,14 +1,10 @@
 macro_rules! warn {
     ($fmt:literal, $ex:expr) => {{
-        use std::env;
         use console::{style, Emoji};
+        use std::env;
         let formatstr = format!($fmt, $ex);
         if env::var("NO_EMOJI").is_ok() {
-            println!(
-                "{} {}",
-                style("!").red(),
-                style(formatstr).red()
-            );
+            println!("{} {}", style("!").red(), style(formatstr).red());
         } else {
             println!(
                 "{} {}",
@@ -21,15 +17,11 @@ macro_rules! warn {
 
 macro_rules! success {
     ($fmt:literal, $ex:expr) => {{
-        use std::env;
         use console::{style, Emoji};
+        use std::env;
         let formatstr = format!($fmt, $ex);
         if env::var("NO_EMOJI").is_ok() {
-            println!(
-                "{} {}",
-                style("✓").green(),
-                style(formatstr).green()
-            );
+            println!("{} {}", style("✓").green(), style(formatstr).green());
         } else {
             println!(
                 "{} {}",
diff --git a/src/verify.rs b/src/verify.rs
index 7a0e9ccd..b98598a8 100644
--- a/src/verify.rs
+++ b/src/verify.rs
@@ -1,7 +1,7 @@
-use std::env;
 use crate::exercise::{CompiledExercise, Exercise, Mode, State};
 use console::style;
 use indicatif::ProgressBar;
+use std::env;
 
 // Verify that the provided container of Exercise objects
 // can be compiled and run without any failures.

From e2c41903ad491df5c0c59c389e3f568dd2485611 Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Sun, 18 Apr 2021 16:07:30 +0200
Subject: [PATCH 098/126] docs: added hint for rustlings list command

Added hint for `rustlings list` to the "Doing exercises" section.
---
 README.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/README.md b/README.md
index 6ffef489..19ec6ce4 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,11 @@ exercise:
 rustlings hint myExercise1
 ```
 
+To check your progress, you can run the following command:
+```bash
+rustlings list
+```
+
 ## Testing yourself
 
 After every couple of sections, there will be a quiz that'll test your knowledge on a bunch of sections at once. These quizzes are found in `exercises/quizN.rs`.

From 1c6f7e4b7b9b3bd36f4da2bb2b69c549cc8bd913 Mon Sep 17 00:00:00 2001
From: Patrick Hintermayer <Zerotask@users.noreply.github.com>
Date: Mon, 19 Apr 2021 09:39:05 +0200
Subject: [PATCH 099/126] feat(list): updated progress percentage

---
 src/main.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index 73647234..3b7a1942 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -179,7 +179,7 @@ fn main() {
                 }
             }
         });
-        let percentage_progress = exercises_done as f32 / exercises.len() as f32;
+        let percentage_progress = exercises_done as f32 / exercises.len() as f32 * 100.0;
         println!(
             "Progress: You completed {} / {} exercises ({:.2} %).",
             exercises_done,

From 2612edc133c8ec6e2c10c13ed9c86019ea6d27d9 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:09:30 +0000
Subject: [PATCH 100/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 6ffef489..ed0095cf 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-85-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-86-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -266,6 +266,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/blerchy"><img src="https://avatars.githubusercontent.com/u/2555355?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Matt Lebl</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=blerchy" title="Code">💻</a></td>
     <td align="center"><a href="http://flakolefluk.dev"><img src="https://avatars.githubusercontent.com/u/11986564?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ignacio Le Fluk</b></sub></a><br /><a href="#content-flakolefluk" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/tlyu"><img src="https://avatars.githubusercontent.com/u/431873?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Taylor Yu</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=tlyu" title="Code">💻</a> <a href="#content-tlyu" title="Content">🖋</a></td>
+    <td align="center"><a href="https://zerotask.github.io"><img src="https://avatars.githubusercontent.com/u/20150243?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Patrick Hintermayer</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Zerotask" title="Code">💻</a></td>
   </tr>
 </table>
 

From 63c942233e8e9fe1171e51acf35d8dc93897471b Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:09:31 +0000
Subject: [PATCH 101/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index c7f10be4..8621df10 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -793,6 +793,15 @@
         "code",
         "content"
       ]
+    },
+    {
+      "login": "Zerotask",
+      "name": "Patrick Hintermayer",
+      "avatar_url": "https://avatars.githubusercontent.com/u/20150243?v=4",
+      "profile": "https://zerotask.github.io",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 72aaa15e6ab4b72b3422f1c6356396e20a2a2bb8 Mon Sep 17 00:00:00 2001
From: Pete Pavlovski <pavlovskipetko@abv.bg>
Date: Tue, 20 Apr 2021 12:15:49 +0300
Subject: [PATCH 102/126] fix(hashmap2): Update incorrect assertion (#660)

The test description says "at least five types of fruit", but the test itself is checking for exactly five types of fruit, which was a bit misleading for newcomers like me :)

A simple change from "==" to ">=" should do the trick and successfully check for the "at least" condition.
---
 exercises/collections/hashmap2.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/collections/hashmap2.rs b/exercises/collections/hashmap2.rs
index c8698fed..0abe19ab 100644
--- a/exercises/collections/hashmap2.rs
+++ b/exercises/collections/hashmap2.rs
@@ -68,7 +68,7 @@ mod tests {
         let mut basket = get_fruit_basket();
         fruit_basket(&mut basket);
         let count_fruit_kinds = basket.len();
-        assert!(count_fruit_kinds == 5);
+        assert!(count_fruit_kinds >= 5);
     }
 
     #[test]

From a941c69f09c7349ff578da348a075a146c1005b6 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:16:15 +0000
Subject: [PATCH 103/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 760565e2..10b7c1cf 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-86-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-87-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -272,6 +272,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="http://flakolefluk.dev"><img src="https://avatars.githubusercontent.com/u/11986564?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ignacio Le Fluk</b></sub></a><br /><a href="#content-flakolefluk" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/tlyu"><img src="https://avatars.githubusercontent.com/u/431873?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Taylor Yu</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=tlyu" title="Code">💻</a> <a href="#content-tlyu" title="Content">🖋</a></td>
     <td align="center"><a href="https://zerotask.github.io"><img src="https://avatars.githubusercontent.com/u/20150243?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Patrick Hintermayer</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Zerotask" title="Code">💻</a></td>
+    <td align="center"><a href="https://petkopavlovski.com/"><img src="https://avatars.githubusercontent.com/u/32264020?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pete Pavlovski</b></sub></a><br /><a href="#content-arthas168" title="Content">🖋</a></td>
   </tr>
 </table>
 

From bdf01aa174533d5908e83a7ed3113b62f4eb6fe3 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:16:16 +0000
Subject: [PATCH 104/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 8621df10..0b490899 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -802,6 +802,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "arthas168",
+      "name": "Pete Pavlovski",
+      "avatar_url": "https://avatars.githubusercontent.com/u/32264020?v=4",
+      "profile": "https://petkopavlovski.com/",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From b4de6594380636817d13c2677ec6f472a964cf43 Mon Sep 17 00:00:00 2001
From: k12ish <45272873+k12ish@users.noreply.github.com>
Date: Tue, 20 Apr 2021 10:18:05 +0100
Subject: [PATCH 105/126] fix(option2): Rename uninformative variables (#675)

Renaming uninformative names like `optional_value`, `value`, `optional_values_vec` and `value` helps users distinguish between the two parts of the task.
---
 exercises/option/option2.rs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/exercises/option/option2.rs b/exercises/option/option2.rs
index a1517d7c..c6b83ece 100644
--- a/exercises/option/option2.rs
+++ b/exercises/option/option2.rs
@@ -4,22 +4,22 @@
 // I AM NOT DONE
 
 fn main() {
-    let optional_value = Some(String::from("rustlings"));
+    let optional_word = Some(String::from("rustlings"));
     // TODO: Make this an if let statement whose value is "Some" type
-    value = optional_value {
-        println!("the value of optional value is: {}", value);
+    word = optional_word {
+        println!("The word is: {}", word);
     } else {
-        println!("The optional value doesn't contain anything!");
+        println!("The optional word doesn't contain anything");
     }
 
-    let mut optional_values_vec: Vec<Option<i8>> = Vec::new();
+    let mut optional_integers_vec: Vec<Option<i8>> = Vec::new();
     for x in 1..10 {
-        optional_values_vec.push(Some(x));
+        optional_integers_vec.push(Some(x));
     }
 
     // TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
     // You can stack `Option<T>`'s into while let and if let
-    value = optional_values_vec.pop() {
-        println!("current value: {}", value);
+    integer = optional_integers_vec.pop() {
+        println!("current value: {}", integer);
     }
 }

From 472f61485e49864d62901ee024ed5c8a18b861a0 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:18:22 +0000
Subject: [PATCH 106/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 10b7c1cf..721c63a0 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-87-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-88-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -273,6 +273,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/tlyu"><img src="https://avatars.githubusercontent.com/u/431873?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Taylor Yu</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=tlyu" title="Code">💻</a> <a href="#content-tlyu" title="Content">🖋</a></td>
     <td align="center"><a href="https://zerotask.github.io"><img src="https://avatars.githubusercontent.com/u/20150243?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Patrick Hintermayer</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Zerotask" title="Code">💻</a></td>
     <td align="center"><a href="https://petkopavlovski.com/"><img src="https://avatars.githubusercontent.com/u/32264020?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pete Pavlovski</b></sub></a><br /><a href="#content-arthas168" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/k12ish"><img src="https://avatars.githubusercontent.com/u/45272873?v=4?s=100" width="100px;" alt=""/><br /><sub><b>k12ish</b></sub></a><br /><a href="#content-k12ish" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 65cdc856aec4f86c7b513d2b85d3357e5a9b3a4f Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:18:23 +0000
Subject: [PATCH 107/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 0b490899..a2473872 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -811,6 +811,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "k12ish",
+      "name": "k12ish",
+      "avatar_url": "https://avatars.githubusercontent.com/u/45272873?v=4",
+      "profile": "https://github.com/k12ish",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 6bd791f2f44aa7f0ad926df767f6b1fa8f12a9a9 Mon Sep 17 00:00:00 2001
From: Shao Yang Hong <hongsy2006@gmail.com>
Date: Tue, 20 Apr 2021 17:19:24 +0800
Subject: [PATCH 108/126] fix(structs): Add 5.3 to structs/README (#652)

Co-authored-by: Shao Yang Hong <shaoyang.hong@ninjavan.co>
---
 exercises/structs/README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/exercises/structs/README.md b/exercises/structs/README.md
index 72e0061b..58e5a6a4 100644
--- a/exercises/structs/README.md
+++ b/exercises/structs/README.md
@@ -5,3 +5,4 @@ Rust has three struct types: a classic C struct, a tuple struct, and a unit stru
 #### Book Sections
 
 - [Structures](https://doc.rust-lang.org/book/ch05-01-defining-structs.html)
+- [Method Syntax](https://doc.rust-lang.org/book/ch05-03-method-syntax.html)

From fab2eb98333434079a3ace6c7d0aa31892bd49cb Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:19:38 +0000
Subject: [PATCH 109/126] docs: update README.md [skip ci]

---
 README.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 721c63a0..2d2cb0ef 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-88-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-89-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -275,6 +275,9 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://petkopavlovski.com/"><img src="https://avatars.githubusercontent.com/u/32264020?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Pete Pavlovski</b></sub></a><br /><a href="#content-arthas168" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/k12ish"><img src="https://avatars.githubusercontent.com/u/45272873?v=4?s=100" width="100px;" alt=""/><br /><sub><b>k12ish</b></sub></a><br /><a href="#content-k12ish" title="Content">🖋</a></td>
   </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/hongshaoyang"><img src="https://avatars.githubusercontent.com/u/19281800?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Shao Yang Hong</b></sub></a><br /><a href="#content-hongshaoyang" title="Content">🖋</a></td>
+  </tr>
 </table>
 
 <!-- markdownlint-restore -->

From eadd41a9ecb05e3278a988f752e77608ded136fa Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Tue, 20 Apr 2021 09:19:39 +0000
Subject: [PATCH 110/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index a2473872..e820b426 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -820,6 +820,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "hongshaoyang",
+      "name": "Shao Yang Hong",
+      "avatar_url": "https://avatars.githubusercontent.com/u/19281800?v=4",
+      "profile": "https://github.com/hongshaoyang",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 9c88ea91266c84901fd46496902610241dab3baf Mon Sep 17 00:00:00 2001
From: apogeeoak <59737221+apogeeoak@users.noreply.github.com>
Date: Tue, 20 Apr 2021 18:52:10 -0400
Subject: [PATCH 111/126] Improved iterators5.rs explanation.

---
 .../standard_library_types/iterators5.rs      | 51 +++++++++++--------
 info.toml                                     | 11 ++--
 2 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/exercises/standard_library_types/iterators5.rs b/exercises/standard_library_types/iterators5.rs
index 65c50e62..2d97bd46 100644
--- a/exercises/standard_library_types/iterators5.rs
+++ b/exercises/standard_library_types/iterators5.rs
@@ -1,11 +1,14 @@
 // iterators5.rs
 
-// Rustling progress is modelled using a hash map. The name of the exercise is
-// the key and the progress is the value. Two counting functions were created
-// to count the number of exercises with a given progress. These counting
-// functions use imperative style for loops. Recreate this counting
-// functionality using iterators.
-// Execute `rustlings hint iterators5` for hints.
+// Let's define a simple model to track Rustlings exercise progress. Progress
+// will be modelled using a hash map. The name of the exercise is the key and
+// the progress is the value. Two counting functions were created to count the
+// number of exercises with a given progress. These counting functions use
+// imperative style for loops. Recreate this counting functionality using
+// iterators. Only the two iterator methods (count_iterator and
+// count_collection_iterator) need to be modified.
+// Execute `rustlings hint
+// iterators5` for hints.
 //
 // Make the code compile and the tests pass.
 
@@ -30,12 +33,14 @@ fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
     count
 }
 
-fn count(map: &HashMap<String, Progress>, value: Progress) -> usize {
+fn count_iterator(map: &HashMap<String, Progress>, value: Progress) -> usize {
+    // map is a hashmap with String keys and Progress values.
+    // map = { "variables1": Complete, "from_str": None, ... }
 }
 
-fn count_stack_for(stack: &[HashMap<String, Progress>], value: Progress) -> usize {
+fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
     let mut count = 0;
-    for map in stack {
+    for map in collection {
         for val in map.values() {
             if val == &value {
                 count += 1;
@@ -45,7 +50,10 @@ fn count_stack_for(stack: &[HashMap<String, Progress>], value: Progress) -> usiz
     count
 }
 
-fn count_stack(stack: &[HashMap<String, Progress>], value: Progress) -> usize {
+fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
+    // collection is a slice of hashmaps.
+    // collection = [{ "variables1": Complete, "from_str": None, ... },
+    //     { "variables2": Complete, ... }, ... ]
 }
 
 #[cfg(test)]
@@ -55,7 +63,7 @@ mod tests {
     #[test]
     fn count_complete() {
         let map = get_map();
-        assert_eq!(3, count(&map, Progress::Complete));
+        assert_eq!(3, count_iterator(&map, Progress::Complete));
     }
 
     #[test]
@@ -63,22 +71,25 @@ mod tests {
         let map = get_map();
         assert_eq!(
             count_for(&map, Progress::Complete),
-            count(&map, Progress::Complete)
+            count_iterator(&map, Progress::Complete)
         );
     }
 
     #[test]
-    fn count_stack_complete() {
-        let stack = get_map_stack();
-        assert_eq!(6, count_stack(&stack, Progress::Complete));
+    fn count_collection_complete() {
+        let collection = get_vec_map();
+        assert_eq!(
+            6,
+            count_collection_iterator(&collection, Progress::Complete)
+        );
     }
 
     #[test]
-    fn count_stack_equals_for() {
-        let stack = get_map_stack();
+    fn count_collection_equals_for() {
+        let collection = get_vec_map();
         assert_eq!(
-            count_stack_for(&stack, Progress::Complete),
-            count_stack(&stack, Progress::Complete)
+            count_collection_for(&collection, Progress::Complete),
+            count_collection_iterator(&collection, Progress::Complete)
         );
     }
 
@@ -96,7 +107,7 @@ mod tests {
         map
     }
 
-    fn get_map_stack() -> Vec<HashMap<String, Progress>> {
+    fn get_vec_map() -> Vec<HashMap<String, Progress>> {
         use Progress::*;
 
         let map = get_map();
diff --git a/info.toml b/info.toml
index 646bb5a5..65f671ac 100644
--- a/info.toml
+++ b/info.toml
@@ -694,7 +694,7 @@ Step 2 & step 2.1:
 Very similar to the lines above and below. You've got this!
 Step 3:
 An iterator goes through all elements in a collection, but what if we've run out of
-elements? What should we expect here? If you're stuck, take a look at 
+elements? What should we expect here? If you're stuck, take a look at
 https://doc.rust-lang.org/std/iter/trait.Iterator.html for some ideas.
 """
 
@@ -749,12 +749,13 @@ hint = """
 The documentation for the std::iter::Iterator trait contains numerous methods
 that would be helpful here.
 
-Return 0 from count_stack to make the code compile in order to test count.
+Return 0 from count_collection_iterator to make the code compile in order to
+test count_iterator.
 
-The stack variable in count_stack is a slice of HashMaps. It needs to be
-converted into an iterator in order to use the iterator methods.
+The collection variable in count_collection_iterator is a slice of HashMaps. It
+needs to be converted into an iterator in order to use the iterator methods.
 
-The fold method can be useful in the count_stack function."""
+The fold method can be useful in the count_collection_iterator function."""
 
 # THREADS
 

From 7928122fcef9ca7834d988b1ec8ca0687478beeb Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Tue, 20 Apr 2021 12:46:49 +0200
Subject: [PATCH 112/126] feat: Replace clap with argh
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

I’ve been wanting to do this for a while, but always procrastinated on it. We’ve been using Clap since the 2.0 rewrite, but Clap is known to be a fairly heavy library. Since Rustlings is usually peoples’ first contact with a Rust compilation, I think it’s in our best interests that this complation is as fast as possible. In effect, replacing Clap with the smaller, structopt-style `argh` reduces the amount of crates needing to be compiled from 82 to 60.

I also think this makes the code way easier to read, we don’t need to use Clap’s methods anymore, but can switch over to using pure Rust methods, e.g., switches are booleans, options are Option<String>s or the like, and subcommands are just structs.
---
 Cargo.lock      | 543 +++++++++++++++++-------------------------------
 Cargo.toml      |   2 +-
 src/exercise.rs |   4 +-
 src/main.rs     | 431 +++++++++++++++++++-------------------
 4 files changed, 405 insertions(+), 575 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 4a4313e7..367881c7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,22 +2,42 @@
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
-version = "0.7.3"
+version = "0.7.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6f484ae0c99fec2e858eb6134949117399f222608d84cadb3f58c1f97c2364c"
+checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
 dependencies = [
  "memchr",
 ]
 
 [[package]]
-name = "ansi_term"
-version = "0.11.0"
+name = "argh"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+checksum = "91792f088f87cdc7a2cfb1d617fa5ea18d7f1dc22ef0e1b5f82f3157cdc522be"
 dependencies = [
- "winapi 0.3.8",
+ "argh_derive",
+ "argh_shared",
 ]
 
+[[package]]
+name = "argh_derive"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4eb0c0c120ad477412dc95a4ce31e38f2113e46bd13511253f79196ca68b067"
+dependencies = [
+ "argh_shared",
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "argh_shared"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "781f336cc9826dbaddb9754cb5db61e64cab4f69668bd19dcc4a0394a86f4cb1"
+
 [[package]]
 name = "assert_cmd"
 version = "0.11.1"
@@ -32,67 +52,49 @@ dependencies = [
 
 [[package]]
 name = "atty"
-version = "0.2.11"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
 dependencies = [
+ "hermit-abi",
  "libc",
- "termion",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "autocfg"
-version = "0.1.4"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e49efa51329a5fd37e7c79db4621af617cd4e3e5bc224939808d076077077bf"
+checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
 [[package]]
 name = "bitflags"
-version = "1.0.4"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
+checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "cfg-if"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b486ce3ccf7ffd79fdeb678eac06a9e6c09fc88d33836340becb8fffe87c5e33"
+checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
 [[package]]
-name = "clap"
-version = "2.33.0"
+name = "cfg-if"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
-dependencies = [
- "ansi_term",
- "atty",
- "bitflags",
- "strsim",
- "textwrap",
- "unicode-width",
- "vec_map",
-]
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "clicolors-control"
-version = "1.0.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73abfd4c73d003a674ce5d2933fca6ce6c42480ea84a5ffe0a2dc39ed56300f9"
+checksum = "90082ee5dcdd64dc4e9e0d37fbf3ee325419e39c0092191e0393df65518f741e"
 dependencies = [
  "atty",
  "lazy_static",
  "libc",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "cloudabi"
-version = "0.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
-dependencies = [
- "bitflags",
+ "winapi 0.3.9",
 ]
 
 [[package]]
@@ -110,23 +112,22 @@ dependencies = [
  "regex",
  "termios",
  "unicode-width",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "console"
-version = "0.8.0"
+version = "0.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b147390a412132d75d10dd3b7b175a69cf5fd95032f7503c7091b8831ba10242"
+checksum = "3993e6445baa160675931ec041a5e03ca84b9c6e32a056150d3aa2bdda0a1f45"
 dependencies = [
- "clicolors-control",
  "encode_unicode",
  "lazy_static",
  "libc",
  "regex",
- "termios",
+ "terminal_size",
  "unicode-width",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
@@ -137,9 +138,9 @@ checksum = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
 
 [[package]]
 name = "encode_unicode"
-version = "0.3.5"
+version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90b2c9496c001e8cb61827acdefad780795c42264c137744cae6f7d9e3450abd"
+checksum = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
 
 [[package]]
 name = "escargot"
@@ -155,20 +156,21 @@ dependencies = [
 
 [[package]]
 name = "filetime"
-version = "0.2.5"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f8c63033fcba1f51ef744505b3cad42510432b904c062afa67ad7ece008429d"
+checksum = "1d34cfa13a63ae058bfa601fe9e313bbdb3746427c1459185464ce0fcf62e1e8"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
  "libc",
  "redox_syscall",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "float-cmp"
-version = "0.4.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "134a8fa843d80a51a5b77d36d42bc2def9edcb0262c914861d08129fd1926600"
+checksum = "e1267f4ac4f343772758f7b1bdcbe767c218bbab93bb432acbf5162bbf85a6c4"
 dependencies = [
  "num-traits",
 ]
@@ -192,12 +194,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "fuchsia-cprng"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
-
 [[package]]
 name = "fuchsia-zircon"
 version = "0.3.3"
@@ -220,13 +216,31 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 
+[[package]]
+name = "heck"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
+dependencies = [
+ "unicode-segmentation",
+]
+
+[[package]]
+name = "hermit-abi"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "indicatif"
 version = "0.10.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "40ecd1e2ee08e6c255ce890f5a99d17000850e664e7acf119fb03b25b0575bfe"
 dependencies = [
- "console 0.8.0",
+ "console 0.14.1",
  "lazy_static",
  "number_prefix",
  "parking_lot",
@@ -235,9 +249,9 @@ dependencies = [
 
 [[package]]
 name = "inotify"
-version = "0.7.0"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24e40d6fd5d64e2082e0c796495c8ef5ad667a96d03e5aaa0becfd9d47bcbfb8"
+checksum = "4816c66d2c8ae673df83366c18341538f234a26d65a9ecea5c348b453ac1d02f"
 dependencies = [
  "bitflags",
  "inotify-sys",
@@ -246,28 +260,36 @@ dependencies = [
 
 [[package]]
 name = "inotify-sys"
-version = "0.1.3"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e74a1aa87c59aeff6ef2cc2fa62d41bc43f54952f55652656b18a02fd5e356c0"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
 dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "instant"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61124eeebbd69b8190558df225adf7e4caafce0d743919e5d6b19652314ec5ec"
+dependencies = [
+ "cfg-if 1.0.0",
+]
+
 [[package]]
 name = "iovec"
-version = "0.1.2"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbe6e417e7d0975db6512b90796e8ce223145ac4e33c377e4a42882a0e88bb08"
+checksum = "b2b3ea6ff95e175473f8ffe6a7eb7c00d054240321b84c57051175fe3c1e075e"
 dependencies = [
  "libc",
- "winapi 0.2.8",
 ]
 
 [[package]]
 name = "itoa"
-version = "0.4.4"
+version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
+checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 
 [[package]]
 name = "kernel32-sys"
@@ -281,52 +303,53 @@ dependencies = [
 
 [[package]]
 name = "lazy_static"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc5729f27f159ddd61f4df6228e827e86643d4d3e7c32183cb30a1c08f604a14"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "lazycell"
-version = "1.2.1"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.58"
+version = "0.2.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6281b86796ba5e4366000be6e9e18bf35580adf9e63fbe2294aadb587613a319"
+checksum = "9385f66bf6105b241aa65a61cb923ef20efc665cb9f9bb50ac2f0c4b7f378d41"
 
 [[package]]
 name = "lock_api"
-version = "0.2.0"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed946d4529956a20f2d63ebe1b69996d5a2137c91913fe3ebbeff957f5bca7ff"
+checksum = "5a3c91c24eae6777794bb1997ad98bbb87daf92890acab859f7eaa4320333176"
 dependencies = [
  "scopeguard",
 ]
 
 [[package]]
 name = "log"
-version = "0.4.6"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
 ]
 
 [[package]]
 name = "memchr"
-version = "2.2.0"
+version = "2.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2efc7bc57c883d4a4d6e3246905283d8dae951bb3bd32f49d6ef297f546e1c39"
+checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
 [[package]]
 name = "mio"
-version = "0.6.19"
+version = "0.6.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83f51996a3ed004ef184e16818edc51fadffe8e7ca68be67f9dee67d84d0ff23"
+checksum = "4afd66f5b91bf2a3bc13fad0e21caedac168ca4c707504e75585648ae80e4cc4"
 dependencies = [
+ "cfg-if 0.1.10",
  "fuchsia-zircon",
  "fuchsia-zircon-sys",
  "iovec",
@@ -341,9 +364,9 @@ dependencies = [
 
 [[package]]
 name = "mio-extras"
-version = "2.0.5"
+version = "2.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
+checksum = "52403fe290012ce777c4626790c8951324a2b9e3316b3143779c72b029742f19"
 dependencies = [
  "lazycell",
  "log",
@@ -353,9 +376,9 @@ dependencies = [
 
 [[package]]
 name = "miow"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
+checksum = "ebd808424166322d4a38da87083bfddd3ac4c131334ed55856112eb06d46944d"
 dependencies = [
  "kernel32-sys",
  "net2",
@@ -365,26 +388,26 @@ dependencies = [
 
 [[package]]
 name = "net2"
-version = "0.2.33"
+version = "0.2.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42550d9fb7b6684a6d404d9fa7250c2eb2646df731d1c06afc06dcee9e1bcf88"
+checksum = "391630d12b68002ae1e25e8f974306474966550ad82dac6886fb8910c19568ae"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "normalize-line-endings"
-version = "0.2.2"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e0a1a39eab95caf4f5556da9289b9e68f0aafac901b2ce80daaf020d3b733a8"
+checksum = "61807f77802ff30975e01f4f071c8ba10c022052f98b3294119f3e615d13e5be"
 
 [[package]]
 name = "notify"
-version = "4.0.15"
+version = "4.0.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "80ae4a7688d1fab81c5bf19c64fc8db920be8d519ce6336ed4e7efe024724dbd"
+checksum = "2599080e87c9bd051ddb11b10074f4da7b1223298df65d4c2ec5bcf309af1533"
 dependencies = [
  "bitflags",
  "filetime",
@@ -395,14 +418,14 @@ dependencies = [
  "mio",
  "mio-extras",
  "walkdir",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "num-traits"
-version = "0.2.8"
+version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
+checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
 dependencies = [
  "autocfg",
 ]
@@ -416,44 +439,36 @@ dependencies = [
  "num-traits",
 ]
 
-[[package]]
-name = "numtoa"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8f8bdf33df195859076e54ab11ee78a1b208382d3a26ec40d142ffc1ecc49ef"
-
 [[package]]
 name = "parking_lot"
-version = "0.8.0"
+version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa7767817701cce701d5585b9c4db3cdd02086398322c1d7e8bf5094a96a2ce7"
+checksum = "6d7744ac029df22dca6284efe4e898991d28e3085c706c972bcd7da4a27a15eb"
 dependencies = [
+ "instant",
  "lock_api",
  "parking_lot_core",
- "rustc_version",
 ]
 
 [[package]]
 name = "parking_lot_core"
-version = "0.5.0"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb88cb1cb3790baa6776844f968fea3be44956cf184fa1be5a03341f5491278c"
+checksum = "fa7a782938e745763fe6907fc6ba86946d72f49fe7e21de074e08128a99fb018"
 dependencies = [
- "cfg-if",
- "cloudabi",
+ "cfg-if 1.0.0",
+ "instant",
  "libc",
- "rand",
  "redox_syscall",
- "rustc_version",
  "smallvec",
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "predicates"
-version = "1.0.1"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53e09015b0d3f5a0ec2d4428f7559bb7b3fff341b4e159fedd1d57fac8b939ff"
+checksum = "eeb433456c1a57cc93554dea3ce40b4c19c4057e41c55d4a0f3d84ea71c325aa"
 dependencies = [
  "difference",
  "float-cmp",
@@ -464,15 +479,15 @@ dependencies = [
 
 [[package]]
 name = "predicates-core"
-version = "1.0.0"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "06075c3a3e92559ff8929e7a280684489ea27fe44805174c3ebd9328dcb37178"
+checksum = "57e35a3326b75e49aa85f5dc6ec15b41108cf5aee58eabb1f274dd18b73c2451"
 
 [[package]]
 name = "predicates-tree"
-version = "1.0.0"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e63c4859013b38a76eca2414c64911fba30def9e3202ac461a2d22831220124"
+checksum = "15f553275e5721409451eb85e15fd9a860a6e5ab4496eb215987502b5f5391f2"
 dependencies = [
  "predicates-core",
  "treeline",
@@ -480,189 +495,54 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "0.4.30"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
+checksum = "a152013215dca273577e18d2bf00fa862b89b24169fb78c4c95aeb07992c9cec"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "0.6.12"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "faf4799c5d274f3868a4aae320a0a182cbd2baee377b378f080e16a23e9d80db"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
 dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "rand"
-version = "0.6.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
-dependencies = [
- "autocfg",
- "libc",
- "rand_chacha",
- "rand_core 0.4.0",
- "rand_hc",
- "rand_isaac",
- "rand_jitter",
- "rand_os",
- "rand_pcg",
- "rand_xorshift",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "rand_chacha"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
-dependencies = [
- "autocfg",
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
-dependencies = [
- "rand_core 0.4.0",
-]
-
-[[package]]
-name = "rand_core"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0e7a549d590831370895ab7ba4ea0c1b6b011d106b5ff2da6eee112615e6dc0"
-
-[[package]]
-name = "rand_hc"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
-dependencies = [
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rand_isaac"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
-dependencies = [
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rand_jitter"
-version = "0.1.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1166d5c91dc97b88d1decc3285bb0a99ed84b05cfd0bc2341bdf2d43fc41e39b"
-dependencies = [
- "libc",
- "rand_core 0.4.0",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "rand_os"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
-dependencies = [
- "cloudabi",
- "fuchsia-cprng",
- "libc",
- "rand_core 0.4.0",
- "rdrand",
- "winapi 0.3.8",
-]
-
-[[package]]
-name = "rand_pcg"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
-dependencies = [
- "autocfg",
- "rand_core 0.4.0",
-]
-
-[[package]]
-name = "rand_xorshift"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
-dependencies = [
- "rand_core 0.3.1",
-]
-
-[[package]]
-name = "rdrand"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
-dependencies = [
- "rand_core 0.3.1",
-]
-
 [[package]]
 name = "redox_syscall"
-version = "0.1.54"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12229c14a0f65c4f1cb046a3b52047cdd9da1f4b30f8a39c5063c8bae515e252"
-
-[[package]]
-name = "redox_termios"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
+checksum = "8270314b5ccceb518e7e578952f0b72b88222d02e8f77f5ecf7abbb673539041"
 dependencies = [
- "redox_syscall",
+ "bitflags",
 ]
 
 [[package]]
 name = "regex"
-version = "1.1.6"
+version = "1.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f0a0bcab2fd7d1d7c54fa9eae6f43eddeb9ce2e7352f8518a814a4f65d60c58"
+checksum = "957056ecddbeba1b26965114e191d2e8589ce74db242b6ea25fc4062427a5c19"
 dependencies = [
  "aho-corasick",
  "memchr",
  "regex-syntax",
- "thread_local",
- "utf8-ranges",
 ]
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.6"
+version = "0.6.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dcfd8681eebe297b81d98498869d4aae052137651ad7b96822f09ceb690d0a96"
-dependencies = [
- "ucd-util",
-]
-
-[[package]]
-name = "rustc_version"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
-dependencies = [
- "semver",
-]
+checksum = "24d5f089152e60f62d28b835fbff2cd2e8dc0baf1ac13343bef92ab7eed84548"
 
 [[package]]
 name = "rustlings"
 version = "4.3.0"
 dependencies = [
+ "argh",
  "assert_cmd",
- "clap",
  "console 0.7.7",
  "glob",
  "indicatif",
@@ -675,54 +555,39 @@ dependencies = [
 
 [[package]]
 name = "ryu"
-version = "0.2.8"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b96a9549dc8d48f2c283938303c4b5a77aa29bfbc5b54b084fb1630408899a8f"
+checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
 
 [[package]]
 name = "same-file"
-version = "1.0.4"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f20c4be53a8a1ff4c1f1b2bd14570d2f634628709752f0702ecdd2b3f9a5267"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
 dependencies = [
  "winapi-util",
 ]
 
 [[package]]
 name = "scopeguard"
-version = "1.0.0"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b42e15e59b18a828bbf5c58ea01debb36b9b096346de35d941dcb89009f24a0d"
-
-[[package]]
-name = "semver"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
-dependencies = [
- "semver-parser",
-]
-
-[[package]]
-name = "semver-parser"
-version = "0.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "serde"
-version = "1.0.92"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32746bf0f26eab52f06af0d0aa1984f641341d06d8d673c693871da2d188c9be"
+checksum = "558dc50e1a5a5fa7112ca2ce4effcb321b0300c0d4ccf0776a9f60cd89031171"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.92"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46a3223d0c9ba936b61c0d2e3e559e3217dbfb8d65d06d26e8b3c25de38bae3e"
+checksum = "b093b7a2bb58203b5da3056c05b4ec1fed827dcfdb37347a8841695263b3d06d"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -731,9 +596,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.39"
+version = "1.0.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a23aa71d4a4d43fdbfaac00eff68ba8a06a51759a89ac3304323e800c4dd40d"
+checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
 dependencies = [
  "itoa",
  "ryu",
@@ -748,21 +613,15 @@ checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 
 [[package]]
 name = "smallvec"
-version = "0.6.9"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4488ae950c49d403731982257768f48fada354a5203fe81f9bb6f43ca9002be"
-
-[[package]]
-name = "strsim"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
+checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 
 [[package]]
 name = "syn"
-version = "0.15.34"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1393e4a97a19c01e900df2aec855a29f71cf02c402e2f443b8d2747c25c5dbe"
+checksum = "48fe99c6bd8b1cc636890bcc071842de909d902c81ac7dab53ba33c421ab8ffb"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -770,44 +629,24 @@ dependencies = [
 ]
 
 [[package]]
-name = "termion"
-version = "1.5.2"
+name = "terminal_size"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dde0593aeb8d47accea5392b39350015b5eccb12c0d98044d856983d89548dea"
+checksum = "86ca8ced750734db02076f44132d802af0b33b09942331f4459dde8636fd2406"
 dependencies = [
  "libc",
- "numtoa",
- "redox_syscall",
- "redox_termios",
+ "winapi 0.3.9",
 ]
 
 [[package]]
 name = "termios"
-version = "0.3.1"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72b620c5ea021d75a735c943269bb07d30c9b77d6ac6b236bc8b5c496ef05625"
+checksum = "411c5bf740737c7918b8b1fe232dca4dc9f8e754b8ad5e20966814001ed0ac6b"
 dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "textwrap"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
-dependencies = [
- "unicode-width",
-]
-
-[[package]]
-name = "thread_local"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
-dependencies = [
- "lazy_static",
-]
-
 [[package]]
 name = "toml"
 version = "0.4.10"
@@ -824,43 +663,31 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7f741b240f1a48843f9b8e0444fb55fb2a4ff67293b50a9179dfd5ea67f8d41"
 
 [[package]]
-name = "ucd-util"
-version = "0.1.3"
+name = "unicode-segmentation"
+version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "535c204ee4d8434478593480b8f86ab45ec9aae0e83c568ca81abf0fd0e88f86"
+checksum = "bb0d2e7be6ae3a5fa87eed5fb451aff96f2573d2694942e40543ae0bbe19c796"
 
 [[package]]
 name = "unicode-width"
-version = "0.1.5"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "882386231c45df4700b275c7ff55b6f3698780a650026380e72dabe76fa46526"
+checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
 
 [[package]]
 name = "unicode-xid"
-version = "0.1.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
-
-[[package]]
-name = "utf8-ranges"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "796f7e48bef87609f7ade7e06495a87d5cd06c7866e6a5cbfceffc558a243737"
-
-[[package]]
-name = "vec_map"
-version = "0.8.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
+checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
 
 [[package]]
 name = "walkdir"
-version = "2.2.7"
+version = "2.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d9d7ed3431229a144296213105a390676cc49c9b6a72bd19f3176c98e129fa1"
+checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
 dependencies = [
  "same-file",
- "winapi 0.3.8",
+ "winapi 0.3.9",
  "winapi-util",
 ]
 
@@ -872,9 +699,9 @@ checksum = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 
 [[package]]
 name = "winapi"
-version = "0.3.8"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
 dependencies = [
  "winapi-i686-pc-windows-gnu",
  "winapi-x86_64-pc-windows-gnu",
@@ -894,11 +721,11 @@ checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
 [[package]]
 name = "winapi-util"
-version = "0.1.2"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7168bab6e1daee33b4557efd0e95d5ca70a03706d39fa5f3fe7a236f584b03c9"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
 dependencies = [
- "winapi 0.3.8",
+ "winapi 0.3.9",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index a0564c37..397eb996 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nicho
 edition = "2018"
 
 [dependencies]
-clap = "2.32.0"
+argh = "0.1.4"
 indicatif = "0.10.3"
 console = "0.7.7"
 notify = "4.0.15"
diff --git a/src/exercise.rs b/src/exercise.rs
index e9d1c1c9..d934cfd3 100644
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -24,7 +24,7 @@ fn temp_file() -> String {
 }
 
 // The mode of the exercise.
-#[derive(Deserialize, Copy, Clone)]
+#[derive(Deserialize, Copy, Clone, Debug)]
 #[serde(rename_all = "lowercase")]
 pub enum Mode {
     // Indicates that the exercise should be compiled as a binary
@@ -42,7 +42,7 @@ pub struct ExerciseList {
 
 // A representation of a rustlings exercise.
 // This is deserialized from the accompanying info.toml file
-#[derive(Deserialize)]
+#[derive(Deserialize, Debug)]
 pub struct Exercise {
     // Name of the exercise
     pub name: String,
diff --git a/src/main.rs b/src/main.rs
index 3b7a1942..5af5febc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,7 @@
 use crate::exercise::{Exercise, ExerciseList};
 use crate::run::run;
 use crate::verify::verify;
-use clap::{crate_version, App, Arg, SubCommand};
+use argh::FromArgs;
 use console::Emoji;
 use notify::DebouncedEvent;
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
@@ -22,85 +22,91 @@ mod exercise;
 mod run;
 mod verify;
 
-fn main() {
-    let matches = App::new("rustlings")
-        .version(crate_version!())
-        .author("Marisa, Carol Nichols")
-        .about("Rustlings is a collection of small exercises to get you used to writing and reading Rust code")
-        .arg(
-            Arg::with_name("nocapture")
-                .long("nocapture")
-                .help("Show outputs from the test exercises")
-        )
-        .subcommand(
-            SubCommand::with_name("verify")
-                .alias("v")
-                .about("Verifies all exercises according to the recommended order")
-        )
-        .subcommand(
-            SubCommand::with_name("watch")
-                .alias("w")
-                .about("Reruns `verify` when files were edited")
-        )
-        .subcommand(
-            SubCommand::with_name("run")
-                .alias("r")
-                .about("Runs/Tests a single exercise")
-                .arg(Arg::with_name("name").required(true).index(1)),
-        )
-        .subcommand(
-            SubCommand::with_name("hint")
-                .alias("h")
-                .about("Returns a hint for the current exercise")
-                .arg(Arg::with_name("name").required(true).index(1)),
-        )
-        .subcommand(
-            SubCommand::with_name("list")
-                .alias("l")
-                .about("Lists the exercises available in rustlings")
-                .arg(
-                    Arg::with_name("paths")
-                        .long("paths")
-                        .short("p")
-                        .conflicts_with("names")
-                        .help("Show only the paths of the exercises")
-                )
-                .arg(
-                    Arg::with_name("names")
-                        .long("names")
-                        .short("n")
-                        .conflicts_with("paths")
-                        .help("Show only the names of the exercises")
-                )
-                .arg(
-                    Arg::with_name("filter")
-                        .long("filter")
-                        .short("f")
-                        .takes_value(true)
-                        .empty_values(false)
-                        .help(
-                            "Provide a string to match the exercise names.\
-                            \nComma separated patterns are acceptable."
-                        )
-                )
-                .arg(
-                    Arg::with_name("unsolved")
-                        .long("unsolved")
-                        .short("u")
-                        .conflicts_with("solved")
-                        .help("Display only exercises not yet solved")
-                )
-                .arg(
-                    Arg::with_name("solved")
-                        .long("solved")
-                        .short("s")
-                        .conflicts_with("unsolved")
-                        .help("Display only exercises that have been solved")
-                )
-        )
-        .get_matches();
+// In sync with crate version
+const VERSION: &str = "4.3.0";
 
-    if matches.subcommand_name().is_none() {
+#[derive(FromArgs, PartialEq, Debug)]
+/// Rustlings is a collection of small exercises to get you used to writing and reading Rust code
+struct Args {
+    /// show outputs from the test exercises
+    #[argh(switch)]
+    nocapture: bool,
+    /// show the executable version
+    #[argh(switch, short = 'v')]
+    version: bool,
+    #[argh(subcommand)]
+    nested: Option<Subcommands>,
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand)]
+enum Subcommands {
+    Verify(VerifyArgs),
+    Watch(WatchArgs),
+    Run(RunArgs),
+    Hint(HintArgs),
+    List(ListArgs),
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "verify")]
+/// Verifies all exercises according to the recommended order
+struct VerifyArgs {}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "watch")]
+/// Reruns `verify` when files were edited
+struct WatchArgs {}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "run")]
+/// Runs/Tests a single exercise
+struct RunArgs {
+    #[argh(positional)]
+    /// the name of the exercise
+    name: String,
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "hint")]
+/// Returns a hint for the given exercise
+struct HintArgs {
+    #[argh(positional)]
+    /// the name of the exercise
+    name: String,
+}
+
+#[derive(FromArgs, PartialEq, Debug)]
+#[argh(subcommand, name = "list")]
+/// Lists the exercises available in Rustlings
+struct ListArgs {
+    #[argh(switch, short = 'p')]
+    /// show only the paths of the exercises
+    paths: bool,
+    #[argh(switch, short = 'n')]
+    /// show only the names of the exercises
+    names: bool,
+    #[argh(option, short = 'f')]
+    /// provide a string to match exercise names
+    /// comma separated patterns are acceptable
+    filter: Option<String>,
+    #[argh(switch, short = 'u')]
+    /// display only exercises not yet solved
+    unsolved: bool,
+    #[argh(switch, short = 's')]
+    /// display only exercises that have been solved
+    solved: bool,
+}
+
+fn main() {
+    let args: Args = argh::from_env();
+
+    if args.version {
+        println!("v{}", VERSION);
+        std::process::exit(0);
+    }
+
+    if args.nested.is_none() {
         println!();
         println!(r#"       welcome to...                      "#);
         println!(r#"                 _   _ _                  "#);
@@ -130,144 +136,129 @@ fn main() {
 
     let toml_str = &fs::read_to_string("info.toml").unwrap();
     let exercises = toml::from_str::<ExerciseList>(toml_str).unwrap().exercises;
-    let verbose = matches.is_present("nocapture");
+    let verbose = args.nocapture;
 
-    // Handle the list command
-    if let Some(list_m) = matches.subcommand_matches("list") {
-        if ["paths", "names"].iter().all(|k| !list_m.is_present(k)) {
-            println!("{:<17}\t{:<46}\t{:<7}", "Name", "Path", "Status");
-        }
-        let filters = list_m.value_of("filter").unwrap_or_default().to_lowercase();
-        let mut exercises_done: u16 = 0;
-        exercises.iter().for_each(|e| {
-            let fname = format!("{}", e.path.display());
-            let filter_cond = filters
-                .split(',')
-                .filter(|f| !f.trim().is_empty())
-                .any(|f| e.name.contains(&f) || fname.contains(&f));
-            let status = if e.looks_done() {
-                exercises_done = exercises_done + 1;
-                "Done"
-            } else {
-                "Pending"
-            };
-            let solve_cond = {
-                (e.looks_done() && list_m.is_present("solved"))
-                    || (!e.looks_done() && list_m.is_present("unsolved"))
-                    || (!list_m.is_present("solved") && !list_m.is_present("unsolved"))
-            };
-            if solve_cond && (filter_cond || !list_m.is_present("filter")) {
-                let line = if list_m.is_present("paths") {
-                    format!("{}\n", fname)
-                } else if list_m.is_present("names") {
-                    format!("{}\n", e.name)
-                } else {
-                    format!("{:<17}\t{:<46}\t{:<7}\n", e.name, fname, status)
-                };
-                // Somehow using println! leads to the binary panicking
-                // when its output is piped.
-                // So, we're handling a Broken Pipe error and exiting with 0 anyway
-                let stdout = std::io::stdout();
-                {
-                    let mut handle = stdout.lock();
-                    handle.write_all(line.as_bytes()).unwrap_or_else(|e| {
-                        match e.kind() {
-                            std::io::ErrorKind::BrokenPipe => std::process::exit(0),
-                            _ => std::process::exit(1),
-                        };
-                    });
-                }
-            }
-        });
-        let percentage_progress = exercises_done as f32 / exercises.len() as f32 * 100.0;
-        println!(
-            "Progress: You completed {} / {} exercises ({:.2} %).",
-            exercises_done,
-            exercises.len(),
-            percentage_progress
-        );
-        std::process::exit(0);
-    }
-
-    // Handle the run command
-    if let Some(ref matches) = matches.subcommand_matches("run") {
-        let name = matches.value_of("name").unwrap();
-
-        let matching_exercise = |e: &&Exercise| name == e.name;
-
-        let exercise = exercises.iter().find(matching_exercise).unwrap_or_else(|| {
-            println!("No exercise found for your given name!");
-            std::process::exit(1)
-        });
-
-        run(&exercise, verbose).unwrap_or_else(|_| std::process::exit(1));
-    }
-
-    if let Some(ref matches) = matches.subcommand_matches("hint") {
-        let name = matches.value_of("name").unwrap();
-
-        let exercise = exercises
-            .iter()
-            .find(|e| name == e.name)
-            .unwrap_or_else(|| {
-                println!("No exercise found for your given name!");
-                std::process::exit(1)
-            });
-
-        println!("{}", exercise.hint);
-    }
-
-    // Handle the verify command
-    if matches.subcommand_matches("verify").is_some() {
-        verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
-    }
-
-    // Handle the watch command
-    if matches.subcommand_matches("watch").is_some() {
-        if let Err(e) = watch(&exercises, verbose) {
-            println!(
-                "Error: Could not watch your progress. Error message was {:?}.",
-                e
-            );
-            println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
-            std::process::exit(1);
-        }
-        println!(
-            "{emoji} All exercises completed! {emoji}",
-            emoji = Emoji("🎉", "★")
-        );
-        println!();
-        println!("+----------------------------------------------------+");
-        println!("|          You made it to the Fe-nish line!          |");
-        println!("+--------------------------  ------------------------+");
-        println!("                          \\/                         ");
-        println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");
-        println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");
-        println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");
-        println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");
-        println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");
-        println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");
-        println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");
-        println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");
-        println!("           ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒         ");
-        println!("             ▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒           ");
-        println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");
-        println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");
-        println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");
-        println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");
-        println!("           ▒▒  ▒▒                      ▒▒  ▒▒         ");
-        println!();
-        println!("We hope you enjoyed learning about the various aspects of Rust!");
-        println!("If you noticed any issues, please don't hesitate to report them to our repo.");
-        println!("You can also contribute your own exercises to help the greater community!");
-        println!();
-        println!("Before reporting an issue or contributing, please read our guidelines:");
-        println!("https://github.com/rust-lang/rustlings/blob/main/CONTRIBUTING.md");
-    }
-
-    if matches.subcommand_name().is_none() {
+    let command = args.nested.unwrap_or_else(|| {
         let text = fs::read_to_string("default_out.txt").unwrap();
         println!("{}", text);
+        std::process::exit(0);
+    });
+    match command {
+        Subcommands::List(subargs) => {
+            if !subargs.paths && !subargs.names {
+                println!("{:<17}\t{:<46}\t{:<7}", "Name", "Path", "Status");
+            }
+            let mut exercises_done: u16 = 0;
+            let filters = subargs.filter.clone().unwrap_or_default().to_lowercase();
+            exercises.iter().for_each(|e| {
+                let fname = format!("{}", e.path.display());
+                let filter_cond = filters
+                    .split(',')
+                    .filter(|f| !f.trim().is_empty())
+                    .any(|f| e.name.contains(&f) || fname.contains(&f));
+                let status = if e.looks_done() {
+                    exercises_done += 1;
+                    "Done"
+                } else {
+                    "Pending"
+                };
+                let solve_cond = {
+                    (e.looks_done() && subargs.solved)
+                        || (!e.looks_done() && subargs.unsolved)
+                        || (!subargs.solved && !subargs.unsolved)
+                };
+                if solve_cond && (filter_cond || subargs.filter.is_none()) {
+                    let line = if subargs.paths {
+                        format!("{}\n", fname)
+                    } else if subargs.names {
+                        format!("{}\n", e.name)
+                    } else {
+                        format!("{:<17}\t{:<46}\t{:<7}\n", e.name, fname, status)
+                    };
+                    // Somehow using println! leads to the binary panicking
+                    // when its output is piped.
+                    // So, we're handling a Broken Pipe error and exiting with 0 anyway
+                    let stdout = std::io::stdout();
+                    {
+                        let mut handle = stdout.lock();
+                        handle.write_all(line.as_bytes()).unwrap_or_else(|e| {
+                            match e.kind() {
+                                std::io::ErrorKind::BrokenPipe => std::process::exit(0),
+                                _ => std::process::exit(1),
+                            };
+                        });
+                    }
+                }
+            });
+            let percentage_progress = exercises_done as f32 / exercises.len() as f32 * 100.0;
+            println!(
+                "Progress: You completed {} / {} exercises ({:.2} %).",
+                exercises_done,
+                exercises.len(),
+                percentage_progress
+            );
+            std::process::exit(0);
+        }
+
+        Subcommands::Run(subargs) => {
+            let exercise = find_exercise(subargs.name, exercises);
+
+            run(&exercise, verbose).unwrap_or_else(|_| std::process::exit(1));
+        }
+
+        Subcommands::Hint(subargs) => {
+            let exercise = find_exercise(subargs.name, exercises);
+
+            println!("{}", exercise.hint);
+        }
+
+        Subcommands::Verify(_subargs) => {
+            verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
+        }
+
+        Subcommands::Watch(_subargs) => {
+            if let Err(e) = watch(&exercises, verbose) {
+                println!(
+                    "Error: Could not watch your progress. Error message was {:?}.",
+                    e
+                );
+                println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
+                std::process::exit(1);
+            }
+            println!(
+                "{emoji} All exercises completed! {emoji}",
+                emoji = Emoji("🎉", "★")
+            );
+            println!();
+            println!("+----------------------------------------------------+");
+            println!("|          You made it to the Fe-nish line!          |");
+            println!("+--------------------------  ------------------------+");
+            println!("                          \\/                         ");
+            println!("     ▒▒          ▒▒▒▒▒▒▒▒      ▒▒▒▒▒▒▒▒          ▒▒   ");
+            println!("   ▒▒▒▒  ▒▒    ▒▒        ▒▒  ▒▒        ▒▒    ▒▒  ▒▒▒▒ ");
+            println!("   ▒▒▒▒  ▒▒  ▒▒            ▒▒            ▒▒  ▒▒  ▒▒▒▒ ");
+            println!(" ░░▒▒▒▒░░▒▒  ▒▒            ▒▒            ▒▒  ▒▒░░▒▒▒▒ ");
+            println!("   ▓▓▓▓▓▓▓▓  ▓▓      ▓▓██  ▓▓  ▓▓██      ▓▓  ▓▓▓▓▓▓▓▓ ");
+            println!("     ▒▒▒▒    ▒▒      ████  ▒▒  ████      ▒▒░░  ▒▒▒▒   ");
+            println!("       ▒▒  ▒▒▒▒▒▒        ▒▒▒▒▒▒        ▒▒▒▒▒▒  ▒▒     ");
+            println!("         ▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▒▒▓▓▒▒▒▒▒▒▒▒       ");
+            println!("           ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒         ");
+            println!("             ▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒           ");
+            println!("           ▒▒  ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒  ▒▒         ");
+            println!("         ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒       ");
+            println!("       ▒▒    ▒▒    ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒    ▒▒    ▒▒     ");
+            println!("       ▒▒  ▒▒    ▒▒                  ▒▒    ▒▒  ▒▒     ");
+            println!("           ▒▒  ▒▒                      ▒▒  ▒▒         ");
+            println!();
+            println!("We hope you enjoyed learning about the various aspects of Rust!");
+            println!(
+                "If you noticed any issues, please don't hesitate to report them to our repo."
+            );
+            println!("You can also contribute your own exercises to help the greater community!");
+            println!();
+            println!("Before reporting an issue or contributing, please read our guidelines:");
+            println!("https://github.com/rust-lang/rustlings/blob/main/CONTRIBUTING.md");
+        }
     }
 }
 
@@ -294,6 +285,18 @@ fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
     });
 }
 
+fn find_exercise(name: String, exercises: Vec<Exercise>) -> Exercise {
+    let matching_exercise = |e: &Exercise| name == e.name;
+
+    exercises
+        .into_iter()
+        .find(matching_exercise)
+        .unwrap_or_else(|| {
+            println!("No exercise found for your given name!");
+            std::process::exit(1)
+        })
+}
+
 fn watch(exercises: &[Exercise], verbose: bool) -> notify::Result<()> {
     /* Clears the terminal with an ANSI escape code.
     Works in UNIX and newer Windows terminals. */

From 6177b6e126852027b689ebab4e0796b2984f987b Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Wed, 21 Apr 2021 14:47:53 +0200
Subject: [PATCH 113/126] chore: Fix integration tests

---
 tests/integration_tests.rs | 67 ++++++++++++++------------------------
 1 file changed, 24 insertions(+), 43 deletions(-)

diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 1bd3bf7e..be9af965 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -24,7 +24,7 @@ fn fails_when_in_wrong_dir() {
 fn verify_all_success() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .arg("v")
+        .arg("verify")
         .current_dir("tests/fixture/success")
         .assert()
         .success();
@@ -34,7 +34,7 @@ fn verify_all_success() {
 fn verify_fails_if_some_fails() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .arg("v")
+        .arg("verify")
         .current_dir("tests/fixture/failure")
         .assert()
         .code(1);
@@ -44,7 +44,7 @@ fn verify_fails_if_some_fails() {
 fn run_single_compile_success() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "compSuccess"])
+        .args(&["run", "compSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .success();
@@ -54,7 +54,7 @@ fn run_single_compile_success() {
 fn run_single_compile_failure() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "compFailure"])
+        .args(&["run", "compFailure"])
         .current_dir("tests/fixture/failure/")
         .assert()
         .code(1);
@@ -64,7 +64,7 @@ fn run_single_compile_failure() {
 fn run_single_test_success() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testSuccess"])
+        .args(&["run", "testSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .success();
@@ -74,7 +74,7 @@ fn run_single_test_success() {
 fn run_single_test_failure() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testFailure"])
+        .args(&["run", "testFailure"])
         .current_dir("tests/fixture/failure/")
         .assert()
         .code(1);
@@ -84,7 +84,7 @@ fn run_single_test_failure() {
 fn run_single_test_not_passed() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testNotPassed.rs"])
+        .args(&["run", "testNotPassed.rs"])
         .current_dir("tests/fixture/failure/")
         .assert()
         .code(1);
@@ -94,7 +94,7 @@ fn run_single_test_not_passed() {
 fn run_single_test_no_filename() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .arg("r")
+        .arg("run")
         .current_dir("tests/fixture/")
         .assert()
         .code(1);
@@ -104,7 +104,7 @@ fn run_single_test_no_filename() {
 fn run_single_test_no_exercise() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "compNoExercise.rs"])
+        .args(&["run", "compNoExercise.rs"])
         .current_dir("tests/fixture/failure")
         .assert()
         .code(1);
@@ -114,7 +114,7 @@ fn run_single_test_no_exercise() {
 fn get_hint_for_single_test() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["h", "testFailure"])
+        .args(&["hint", "testFailure"])
         .current_dir("tests/fixture/failure")
         .assert()
         .code(0)
@@ -131,10 +131,15 @@ fn all_exercises_require_confirmation() {
             file.read_to_string(&mut s).unwrap();
             s
         };
-        source.matches("// I AM NOT DONE").next().unwrap_or_else(|| panic!(
-            "There should be an `I AM NOT DONE` annotation in {:?}",
-            path
-        ));
+        source
+            .matches("// I AM NOT DONE")
+            .next()
+            .unwrap_or_else(|| {
+                panic!(
+                    "There should be an `I AM NOT DONE` annotation in {:?}",
+                    path
+                )
+            });
     }
 }
 
@@ -142,7 +147,7 @@ fn all_exercises_require_confirmation() {
 fn run_compile_exercise_does_not_prompt() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "pending_exercise"])
+        .args(&["run", "pending_exercise"])
         .current_dir("tests/fixture/state")
         .assert()
         .code(0)
@@ -153,7 +158,7 @@ fn run_compile_exercise_does_not_prompt() {
 fn run_test_exercise_does_not_prompt() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "pending_test_exercise"])
+        .args(&["run", "pending_test_exercise"])
         .current_dir("tests/fixture/state")
         .assert()
         .code(0)
@@ -164,7 +169,7 @@ fn run_test_exercise_does_not_prompt() {
 fn run_single_test_success_with_output() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["--nocapture", "r", "testSuccess"])
+        .args(&["--nocapture", "run", "testSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .code(0)
@@ -175,7 +180,7 @@ fn run_single_test_success_with_output() {
 fn run_single_test_success_without_output() {
     Command::cargo_bin("rustlings")
         .unwrap()
-        .args(&["r", "testSuccess"])
+        .args(&["run", "testSuccess"])
         .current_dir("tests/fixture/success/")
         .assert()
         .code(0)
@@ -192,26 +197,6 @@ fn run_rustlings_list() {
         .success();
 }
 
-#[test]
-fn run_rustlings_list_conflicting_display_options() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(&["list", "--names", "--paths"])
-        .current_dir("tests/fixture/success")
-        .assert()
-        .failure();
-}
-
-#[test]
-fn run_rustlings_list_conflicting_solve_options() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(&["list", "--solved", "--unsolved"])
-        .current_dir("tests/fixture/success")
-        .assert()
-        .failure();
-}
-
 #[test]
 fn run_rustlings_list_no_pending() {
     Command::cargo_bin("rustlings")
@@ -231,10 +216,7 @@ fn run_rustlings_list_both_done_and_pending() {
         .current_dir("tests/fixture/state")
         .assert()
         .success()
-        .stdout(
-            predicates::str::contains("Done")
-                .and(predicates::str::contains("Pending"))
-        );
+        .stdout(predicates::str::contains("Done").and(predicates::str::contains("Pending")));
 }
 
 #[test]
@@ -258,4 +240,3 @@ fn run_rustlings_list_without_done() {
         .success()
         .stdout(predicates::str::contains("Done").not());
 }
-

From 81be40448777fa338ebced3b0bfc1b32d6370313 Mon Sep 17 00:00:00 2001
From: Brandon Macer <bobbysox322@gmail.com>
Date: Wed, 21 Apr 2021 08:50:03 -0400
Subject: [PATCH 114/126] feat(arc1): Add more details to description and hint
 (#710)

Co-authored-by: bmacer <bmacer@cisco.com>
Co-authored-by: marisa <mokou@fastmail.com>
Co-authored-by: Roberto Vidal <vidal.roberto.j@gmail.com>
---
 exercises/standard_library_types/arc1.rs | 19 +++++++++++++++++--
 info.toml                                |  7 ++++++-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs
index 4ad649f1..d167380c 100644
--- a/exercises/standard_library_types/arc1.rs
+++ b/exercises/standard_library_types/arc1.rs
@@ -1,7 +1,21 @@
 // arc1.rs
+// In this exercise, we are given a Vec of u32 called "numbers" with values ranging
+// from 0 to 99 -- [ 0, 1, 2, ..., 98, 99 ]
+// We would like to use this set of numbers within 8 different threads simultaneously.
+// Each thread is going to get the sum of every eighth value, with an offset.
+// The first thread (offset 0), will sum 0, 8, 16, ...
+// The second thread (offset 1), will sum 1, 9, 17, ...
+// The third thread (offset 2), will sum 2, 10, 18, ...
+// ...
+// The eighth thread (offset 7), will sum 7, 15, 23, ...
+
+// Because we are using threads, our values need to be thread-safe.  Therefore,
+// we are using Arc.  We need to make a change in each of the two TODOs.
+
+
 // Make this code compile by filling in a value for `shared_numbers` where the
-// TODO comment is and create an initial binding for `child_numbers`
-// somewhere. Try not to create any copies of the `numbers` Vec!
+// first TODO comment is, and create an initial binding for `child_numbers`
+// where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` for hints :)
 
 // I AM NOT DONE
@@ -16,6 +30,7 @@ fn main() {
     let mut joinhandles = Vec::new();
 
     for offset in 0..8 {
+        let child_numbers = // TODO
         joinhandles.push(thread::spawn(move || {
             let mut i = offset;
             let mut sum = 0;
diff --git a/info.toml b/info.toml
index 36dcbe90..82e11952 100644
--- a/info.toml
+++ b/info.toml
@@ -679,7 +679,12 @@ to avoid creating a copy of `numbers`, you'll need to create `child_numbers`
 inside the loop but still in the main thread.
 
 `child_numbers` should be a clone of the Arc of the numbers instead of a
-thread-local copy of the numbers."""
+thread-local copy of the numbers.
+
+This is a simple exercise if you understand the underlying concepts, but if this
+is too much of a struggle, consider reading through all of Chapter 16 in the book:
+https://doc.rust-lang.org/stable/book/ch16-00-concurrency.html
+"""
 
 [[exercises]]
 name = "iterators1"

From 293dfb35d53aba5f9566f980197f93545ed2216d Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Wed, 21 Apr 2021 12:50:26 +0000
Subject: [PATCH 115/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 2d2cb0ef..e76a04dc 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-89-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-90-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -277,6 +277,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/hongshaoyang"><img src="https://avatars.githubusercontent.com/u/19281800?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Shao Yang Hong</b></sub></a><br /><a href="#content-hongshaoyang" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/bmacer"><img src="https://avatars.githubusercontent.com/u/13931806?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Brandon Macer</b></sub></a><br /><a href="#content-bmacer" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 8d0490bd70c7f4227a5aa43b259359a13117435d Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Wed, 21 Apr 2021 12:50:27 +0000
Subject: [PATCH 116/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index e820b426..2820d18a 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -829,6 +829,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "bmacer",
+      "name": "Brandon Macer",
+      "avatar_url": "https://avatars.githubusercontent.com/u/13931806?v=4",
+      "profile": "https://github.com/bmacer",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,

From 347f30bd867343c5ace1097e085a1f7e356553f7 Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Wed, 21 Apr 2021 16:21:56 +0200
Subject: [PATCH 117/126] fix(main): Let find_exercise work with borrows

---
 src/main.rs | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 5af5febc..a95a09d9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -201,13 +201,13 @@ fn main() {
         }
 
         Subcommands::Run(subargs) => {
-            let exercise = find_exercise(subargs.name, exercises);
+            let exercise = find_exercise(&subargs.name, &exercises);
 
             run(&exercise, verbose).unwrap_or_else(|_| std::process::exit(1));
         }
 
         Subcommands::Hint(subargs) => {
-            let exercise = find_exercise(subargs.name, exercises);
+            let exercise = find_exercise(&subargs.name, &exercises);
 
             println!("{}", exercise.hint);
         }
@@ -285,14 +285,12 @@ fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
     });
 }
 
-fn find_exercise(name: String, exercises: Vec<Exercise>) -> Exercise {
-    let matching_exercise = |e: &Exercise| name == e.name;
-
+fn find_exercise<'a>(name: &str, exercises: &'a [Exercise]) -> &'a Exercise {
     exercises
-        .into_iter()
-        .find(matching_exercise)
+        .iter()
+        .find(|e| e.name == name)
         .unwrap_or_else(|| {
-            println!("No exercise found for your given name!");
+            println!("No exercise found for '{}'!", name);
             std::process::exit(1)
         })
 }

From 1120db57a6c20966184eb8f731804604270ff2f1 Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Thu, 22 Apr 2021 21:32:29 +0200
Subject: [PATCH 118/126] docs(errors): add additional help for Result/Boxing

add additional help information provided by the rust by example book
---
 exercises/error_handling/README.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/exercises/error_handling/README.md b/exercises/error_handling/README.md
index 77a58d18..478510a4 100644
--- a/exercises/error_handling/README.md
+++ b/exercises/error_handling/README.md
@@ -3,3 +3,9 @@ For this exercise check out the sections:
 - [Generics](https://doc.rust-lang.org/book/ch10-01-syntax.html)
 
 of the Rust Book.
+
+or alternatively, check out the sections:
+- [Result](https://doc.rust-lang.org/rust-by-example/error/result.html)
+- [Boxing errors](https://doc.rust-lang.org/rust-by-example/error/multiple_error_types/boxing_errors.html)
+  
+of the Rust By Example Book.

From f253103a314b9cdbda1d6271015cf64e5b2347bd Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Thu, 22 Apr 2021 22:11:04 +0200
Subject: [PATCH 119/126] docs(generics): add bounds help

add help for bounds provided by the rust by example book
---
 exercises/generics/README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/exercises/generics/README.md b/exercises/generics/README.md
index 7105f06f..12170d4a 100644
--- a/exercises/generics/README.md
+++ b/exercises/generics/README.md
@@ -4,4 +4,5 @@ In this section you'll learn about saving yourself many lines of code with gener
 
 ### Book Sections
 
-- [Generic Data Types](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html)
\ No newline at end of file
+- [Generic Data Types](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html)
+- [Bounds](https://doc.rust-lang.org/rust-by-example/generics/bounds.html)

From 249ad44cc03974fd34708c23d9832b1729c6e844 Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Fri, 23 Apr 2021 19:54:31 +0200
Subject: [PATCH 120/126] docs(exercises): updated all exercises readme files

all exercises readme files now have a unified structure and a description
---
 exercises/clippy/README.md                 |  6 ++++--
 exercises/collections/README.md            |  6 ++++--
 exercises/conversions/README.md            |  9 +++++----
 exercises/enums/README.md                  |  4 ++--
 exercises/error_handling/README.md         | 14 +++++++-------
 exercises/functions/README.md              |  4 ++--
 exercises/generics/README.md               |  9 ++++++---
 exercises/if/README.md                     |  4 ++--
 exercises/macros/README.md                 |  4 ++--
 exercises/modules/README.md                |  4 ++--
 exercises/move_semantics/README.md         |  4 ++--
 exercises/option/README.md                 | 15 ++++++++++++---
 exercises/primitive_types/README.md        |  4 ++--
 exercises/standard_library_types/README.md | 11 ++++++++---
 exercises/strings/README.md                |  4 ++--
 exercises/structs/README.md                |  4 ++--
 exercises/tests/README.md                  |  4 ++--
 exercises/threads/README.md                | 10 +++++++++-
 exercises/traits/README.md                 | 11 +++++------
 exercises/variables/README.md              |  8 +++++---
 20 files changed, 85 insertions(+), 54 deletions(-)

diff --git a/exercises/clippy/README.md b/exercises/clippy/README.md
index 60a12fe5..55438af6 100644
--- a/exercises/clippy/README.md
+++ b/exercises/clippy/README.md
@@ -1,8 +1,10 @@
-### Clippy
+# Clippy
 
 The Clippy tool is a collection of lints to analyze your code so you can catch common mistakes and improve your Rust code.
 
 If you used the installation script for Rustlings, Clippy should be already installed.
 If not you can install it manually via `rustup component add clippy`.
 
-For more information about Clippy lints, please see [their documentation page](https://rust-lang.github.io/rust-clippy/master/).
+## Further information
+
+- [GitHub Repository](https://github.com/rust-lang/rust-clippy).
diff --git a/exercises/collections/README.md b/exercises/collections/README.md
index af87863b..0291bc87 100644
--- a/exercises/collections/README.md
+++ b/exercises/collections/README.md
@@ -1,4 +1,4 @@
-### Collections
+# Collections
 
 Rust’s standard library includes a number of very useful data
 structures called collections. Most other data types represent one
@@ -17,4 +17,6 @@ structures that are used very often in Rust programs:
   You may also know this by the names [*unordered map* in C++](https://en.cppreference.com/w/cpp/container/unordered_map), 
   [*dictionary* in Python](https://docs.python.org/3/tutorial/datastructures.html#dictionaries) or an *associative array* in other languages.
 
-[Rust book chapter](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)
+## Further information
+
+- [Storing Lists of Values with Vectors](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)
diff --git a/exercises/conversions/README.md b/exercises/conversions/README.md
index 114bd428..8d7da93e 100644
--- a/exercises/conversions/README.md
+++ b/exercises/conversions/README.md
@@ -1,5 +1,4 @@
-### Type conversions
-
+# Type conversions
 
 Rust offers a multitude of ways to convert a value of a given type into another type.
 
@@ -15,6 +14,8 @@ Furthermore, the `std::str` module offers a trait called [`FromStr`](https://doc
 
 These should be the main ways ***within the standard library*** to convert data into your desired types.
 
-#### Book Sections
+## Further information
 
-These are not directly covered in the book, but the standard library has great documentation for [conversions here](https://doc.rust-lang.org/std/convert/index.html). The `FromStr` trait is also covered [here](https://doc.rust-lang.org/std/str/trait.FromStr.html).
\ No newline at end of file
+These are not directly covered in the book, but the standard library has a great documentation for it.
+- [conversions](https://doc.rust-lang.org/std/convert/index.html)
+- [`FromStr` trait](https://doc.rust-lang.org/std/str/trait.FromStr.html)
\ No newline at end of file
diff --git a/exercises/enums/README.md b/exercises/enums/README.md
index 091f5d04..30d4d91d 100644
--- a/exercises/enums/README.md
+++ b/exercises/enums/README.md
@@ -1,10 +1,10 @@
-### Enums
+# Enums
 
 Rust allows you to define types called "enums" which enumerate possible values.
 Enums are a feature in many languages, but their capabilities differ in each language. Rust’s enums are most similar to algebraic data types in functional languages, such as F#, OCaml, and Haskell.
 Useful in combination with enums is Rust's "pattern matching" facility, which makes it easy to run different code for different values of an enumeration.
 
-#### Book Sections
+## Further information
 
 - [Enums](https://doc.rust-lang.org/book/ch06-00-enums.html)
 - [Pattern syntax](https://doc.rust-lang.org/book/ch18-03-pattern-syntax.html)
diff --git a/exercises/error_handling/README.md b/exercises/error_handling/README.md
index 478510a4..5255ace9 100644
--- a/exercises/error_handling/README.md
+++ b/exercises/error_handling/README.md
@@ -1,11 +1,11 @@
-For this exercise check out the sections:
+# Error handling
+Most errors aren’t serious enough to require the program to stop entirely. 
+Sometimes, when a function fails, it’s for a reason that you can easily interpret and respond to.
+For example, if you try to open a file and that operation fails because the file doesn’t exist, you might want to create the file instead of terminating the process.
+
+## Further information
+
 - [Error Handling](https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html)
 - [Generics](https://doc.rust-lang.org/book/ch10-01-syntax.html)
-
-of the Rust Book.
-
-or alternatively, check out the sections:
 - [Result](https://doc.rust-lang.org/rust-by-example/error/result.html)
 - [Boxing errors](https://doc.rust-lang.org/rust-by-example/error/multiple_error_types/boxing_errors.html)
-  
-of the Rust By Example Book.
diff --git a/exercises/functions/README.md b/exercises/functions/README.md
index 351ae023..66547bd4 100644
--- a/exercises/functions/README.md
+++ b/exercises/functions/README.md
@@ -1,7 +1,7 @@
-### Functions
+# Functions
 
 Here, you'll learn how to write functions and how Rust's compiler can trace things way back.
 
-#### Book Sections
+## Further information
 
 - [How Functions Work](https://doc.rust-lang.org/book/ch03-03-how-functions-work.html)
diff --git a/exercises/generics/README.md b/exercises/generics/README.md
index 12170d4a..de46d503 100644
--- a/exercises/generics/README.md
+++ b/exercises/generics/README.md
@@ -1,8 +1,11 @@
-### Generics
+# Generics
 
-In this section you'll learn about saving yourself many lines of code with generics!
+Generics is the topic of generalizing types and functionalities to broader cases.
+This is extremely useful for reducing code duplication in many ways, but can call for rather involving syntax.
+Namely, being generic requires taking great care to specify over which types a generic type is actually considered valid.
+The simplest and most common use of generics is for type parameters.
 
-### Book Sections
+## Further information
 
 - [Generic Data Types](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html)
 - [Bounds](https://doc.rust-lang.org/rust-by-example/generics/bounds.html)
diff --git a/exercises/if/README.md b/exercises/if/README.md
index b1157218..528d9886 100644
--- a/exercises/if/README.md
+++ b/exercises/if/README.md
@@ -1,7 +1,7 @@
-### If
+# If
 
 `if`, the most basic type of control flow, is what you'll learn here.
 
-#### Book Sections
+## Further information
 
 - [Control Flow - if expressions](https://doc.rust-lang.org/book/ch03-05-control-flow.html#if-expressions)
diff --git a/exercises/macros/README.md b/exercises/macros/README.md
index b48b880a..319d8408 100644
--- a/exercises/macros/README.md
+++ b/exercises/macros/README.md
@@ -1,10 +1,10 @@
-### Macros
+# Macros
 
 Rust's macro system is very powerful, but also kind of difficult to wrap your
 head around. We're not going to teach you how to write your own fully-featured
 macros. Instead, we'll show you how to use and create them.
 
-#### Book Sections
+## Further information
 
 - [Macros](https://doc.rust-lang.org/book/ch19-06-macros.html)
 - [The Little Book of Rust Macros](https://danielkeep.github.io/tlborm/book/index.html)
diff --git a/exercises/modules/README.md b/exercises/modules/README.md
index bb765106..6582b000 100644
--- a/exercises/modules/README.md
+++ b/exercises/modules/README.md
@@ -1,7 +1,7 @@
-### Modules
+# Modules
 
 In this section we'll give you an introduction to Rust's module system.
 
-#### Book Sections
+## Further information
 
 - [The Module System](https://doc.rust-lang.org/book/ch07-02-defining-modules-to-control-scope-and-privacy.html)
diff --git a/exercises/move_semantics/README.md b/exercises/move_semantics/README.md
index 6842af7c..54ddd8e6 100644
--- a/exercises/move_semantics/README.md
+++ b/exercises/move_semantics/README.md
@@ -1,8 +1,8 @@
-### Move Semantics
+# Move Semantics
 
 These exercises are adapted from [pnkfelix](https://github.com/pnkfelix)'s [Rust Tutorial](https://pnkfelix.github.io/rust-examples-icfp2014/) -- Thank you Felix!!!
 
-#### Book Sections
+## Further information
 
 For this section, the book links are especially important.
 
diff --git a/exercises/option/README.md b/exercises/option/README.md
index d17b79cc..a304bb44 100644
--- a/exercises/option/README.md
+++ b/exercises/option/README.md
@@ -1,8 +1,17 @@
-### Option
+# Option
 
-#### Book Sections
+Type Option represents an optional value: every Option is either Some and contains a value, or None, and does not. 
+Option types are very common in Rust code, as they have a number of uses:
+- Initial values
+- Return values for functions that are not defined over their entire input range (partial functions)
+- Return value for otherwise reporting simple errors, where None is returned on error
+- Optional struct fields
+- Struct fields that can be loaned or "taken"
+- Optional function arguments
+- Nullable pointers
+- Swapping things out of difficult situations
 
-To learn about Option<T>, check out these links:
+## Further Information
 
 - [Option Enum Format](https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-enum-definitions)
 - [Option Module Documentation](https://doc.rust-lang.org/std/option/)
diff --git a/exercises/primitive_types/README.md b/exercises/primitive_types/README.md
index daa70eea..cea69b02 100644
--- a/exercises/primitive_types/README.md
+++ b/exercises/primitive_types/README.md
@@ -1,9 +1,9 @@
-### Primitive Types
+# Primitive Types
 
 Rust has a couple of basic types that are directly implemented into the
 compiler. In this section, we'll go through the most important ones.
 
-#### Book Sections
+## Further information
 
 - [Data Types](https://doc.rust-lang.org/stable/book/ch03-02-data-types.html)
 - [The Slice Type](https://doc.rust-lang.org/stable/book/ch04-03-slices.html)
diff --git a/exercises/standard_library_types/README.md b/exercises/standard_library_types/README.md
index 8b53dd81..809d61fe 100644
--- a/exercises/standard_library_types/README.md
+++ b/exercises/standard_library_types/README.md
@@ -1,5 +1,10 @@
-For the Box exercise check out the chapter [Using Box to Point to Data on the Heap](https://doc.rust-lang.org/book/ch15-01-box.html).
+# Standard library types
 
-For the Arc exercise check out the chapter [Shared-State Concurrency](https://doc.rust-lang.org/book/ch16-03-shared-state.html) of the Rust Book.
+This section will teach you about Box, Shared-State Concurrency and Iterators.
 
-For the Iterator exercise check out the chapters [Iterator](https://doc.rust-lang.org/book/ch13-02-iterators.html) of the Rust Book and the [Iterator documentation](https://doc.rust-lang.org/stable/std/iter/).
+## Further information
+
+- [Using Box to Point to Data on the Heap](https://doc.rust-lang.org/book/ch15-01-box.html)
+- [Shared-State Concurrency](https://doc.rust-lang.org/book/ch16-03-shared-state.html)
+- [Iterator](https://doc.rust-lang.org/book/ch13-02-iterators.html)
+- [Iterator documentation](https://doc.rust-lang.org/stable/std/iter/)
diff --git a/exercises/strings/README.md b/exercises/strings/README.md
index 38d24c84..fa2104cc 100644
--- a/exercises/strings/README.md
+++ b/exercises/strings/README.md
@@ -1,9 +1,9 @@
-### Strings
+# Strings
 
 Rust has two string types, a string slice (`&str`) and an owned string (`String`).
 We're not going to dictate when you should use which one, but we'll show you how
 to identify and create them, as well as use them.
 
-#### Book Sections
+## Further information
 
 - [Strings](https://doc.rust-lang.org/book/ch08-02-strings.html)
diff --git a/exercises/structs/README.md b/exercises/structs/README.md
index 58e5a6a4..3fc1fdc9 100644
--- a/exercises/structs/README.md
+++ b/exercises/structs/README.md
@@ -1,8 +1,8 @@
-### Structs
+# Structs
 
 Rust has three struct types: a classic C struct, a tuple struct, and a unit struct.
 
-#### Book Sections
+## Further information
 
 - [Structures](https://doc.rust-lang.org/book/ch05-01-defining-structs.html)
 - [Method Syntax](https://doc.rust-lang.org/book/ch05-03-method-syntax.html)
diff --git a/exercises/tests/README.md b/exercises/tests/README.md
index dbb14a83..27c6818d 100644
--- a/exercises/tests/README.md
+++ b/exercises/tests/README.md
@@ -1,7 +1,7 @@
-### Tests
+# Tests
 
 Going out of order from the book to cover tests -- many of the following exercises will ask you to make tests pass!
 
-#### Book Sections
+## Further information
 
 - [Writing Tests](https://doc.rust-lang.org/book/ch11-01-writing-tests.html)
diff --git a/exercises/threads/README.md b/exercises/threads/README.md
index 2024292f..d0866947 100644
--- a/exercises/threads/README.md
+++ b/exercises/threads/README.md
@@ -1 +1,9 @@
-For this exercise check out the [Dining Philosophers example](https://doc.rust-lang.org/1.4.0/book/dining-philosophers.html) and the chapter [Concurrency](https://doc.rust-lang.org/book/ch16-01-threads.html) of the Rust Book.
\ No newline at end of file
+# Threads
+
+In most current operating systems, an executed program’s code is run in a process, and the operating system manages multiple processes at once.
+Within your program, you can also have independent parts that run simultaneously. The features that run these independent parts are called threads.
+
+## Further information
+
+- [Dining Philosophers example](https://doc.rust-lang.org/1.4.0/book/dining-philosophers.html)
+- [Using Threads to Run Code Simultaneously](https://doc.rust-lang.org/book/ch16-01-threads.html)
diff --git a/exercises/traits/README.md b/exercises/traits/README.md
index 8cd03ec4..de67acd0 100644
--- a/exercises/traits/README.md
+++ b/exercises/traits/README.md
@@ -1,4 +1,4 @@
-### Traits
+# Traits
 
 A trait is a collection of methods.
 
@@ -7,14 +7,13 @@ Data types can implement traits. To do so, the methods making up the trait are d
 In this way, traits are somewhat similar to Java interfaces and C++ abstract classes.
 
 Some additional common Rust traits include:
-
-+ `Clone` (the `clone` method),
-+ `Display` (which allows formatted display via `{}`), and
-+ `Debug` (which allows formatted display via `{:?}`).
+- `Clone` (the `clone` method)
+- `Display` (which allows formatted display via `{}`)
+- `Debug` (which allows formatted display via `{:?}`)
 
 Because traits indicate shared behavior between data types, they are useful when writing generics.
 
 
-#### Book Sections
+## Further information
 
 - [Traits](https://doc.rust-lang.org/book/ch10-02-traits.html)
diff --git a/exercises/variables/README.md b/exercises/variables/README.md
index 1e2eb596..11a7a78a 100644
--- a/exercises/variables/README.md
+++ b/exercises/variables/README.md
@@ -1,7 +1,9 @@
-### Variables
+# Variables
 
-Here you'll learn about simple variables.
+In Rust, variables are immutable by default.
+When a variable is immutable, once a value is bound to a name, you can’t change that value.
+You can make them mutable by adding mut in front of the variable name.
 
-#### Book Sections
+## Further information
 
 - [Variables and Mutability](https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html)

From eefa6562327cd537fc33b1688caf8d8512ef46de Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Fri, 23 Apr 2021 20:07:32 +0200
Subject: [PATCH 121/126] chore(deps): update cargo dependencies

---
 Cargo.lock | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 367881c7..fb361569 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -522,9 +522,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.4.5"
+version = "1.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "957056ecddbeba1b26965114e191d2e8589ce74db242b6ea25fc4062427a5c19"
+checksum = "2a26af418b574bd56588335b3a3659a65725d4e636eb1016c2f9e3b38c7cc759"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -607,9 +607,9 @@ dependencies = [
 
 [[package]]
 name = "slab"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
+checksum = "f173ac3d1a7e3b28003f40de0b5ce7fe2710f9b9dc3fc38664cebee46b3b6527"
 
 [[package]]
 name = "smallvec"
@@ -619,9 +619,9 @@ checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 
 [[package]]
 name = "syn"
-version = "1.0.69"
+version = "1.0.70"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "48fe99c6bd8b1cc636890bcc071842de909d902c81ac7dab53ba33c421ab8ffb"
+checksum = "b9505f307c872bab8eb46f77ae357c8eba1fdacead58ee5a850116b1d7f82883"
 dependencies = [
  "proc-macro2",
  "quote",

From cf42ddc4497a2577e8c8e9206523322b3a2b9fc2 Mon Sep 17 00:00:00 2001
From: Zerotask <Zerotask@users.noreply.github.com>
Date: Fri, 23 Apr 2021 20:28:55 +0200
Subject: [PATCH 122/126] chore(watch): add hint for the exercises README.md

rustlings watch will now show an additional hint for the corresponding README.me
---
 src/main.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index a95a09d9..bc1b71e4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -264,7 +264,7 @@ fn main() {
 
 fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
     let failed_exercise_hint = Arc::clone(failed_exercise_hint);
-    println!("Type 'hint' to get help or 'clear' to clear the screen");
+    println!("Type 'hint' or open the corresponding README.md file to get help or type 'clear' to clear the screen.");
     thread::spawn(move || loop {
         let mut input = String::new();
         match io::stdin().read_line(&mut input) {

From 84461c20cbaf97a67baa55afc16989aab3e3c02d Mon Sep 17 00:00:00 2001
From: mokou <mokou@fastmail.com>
Date: Sat, 24 Apr 2021 11:57:00 +0200
Subject: [PATCH 123/126] release: 4.4.0

---
 CHANGELOG.md | 45 +++++++++++++++++++++++++++++++++++++++++++++
 Cargo.lock   |  2 +-
 Cargo.toml   |  2 +-
 README.md    |  2 +-
 src/main.rs  |  2 +-
 5 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3988826e..1686bdd6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,48 @@
+<a name="4.4.0"></a>
+## 4.4.0 (2021-04-24)
+
+
+#### Bug Fixes
+
+*   Fix spelling error in main.rs ([91ee27f2](https://github.com/rust-lang/rustlings/commit/91ee27f22bd3797a9db57e5fd430801c170c5db8))
+*   typo in default out text ([644c49f1](https://github.com/rust-lang/rustlings/commit/644c49f1e04cbb24e95872b3a52b07d692ae3bc8))
+* **collections:**  Naming exercises for vectors and hashmap ([bef39b12](https://github.com/rust-lang/rustlings/commit/bef39b125961310b34b34871e480a82e82af4678))
+* **from_str:**
+  *  Correct typos ([5f7c89f8](https://github.com/rust-lang/rustlings/commit/5f7c89f85db1f33da01911eaa479c3a2d4721678))
+  *  test for error instead of unwrap/should_panic ([15e71535](https://github.com/rust-lang/rustlings/commit/15e71535f37cfaed36e22eb778728d186e2104ab))
+  *   use trait objects for from_str ([c3e7b831](https://github.com/rust-lang/rustlings/commit/c3e7b831786c9172ed8bd5d150f3c432f242fba9))
+* **functions3:**  improve function argument type (#687) ([a6509cc4](https://github.com/rust-lang/rustlings/commit/a6509cc4d545d8825f01ddf7ee37823b372154dd))
+* **hashmap2:**  Update incorrect assertion (#660) ([72aaa15e](https://github.com/rust-lang/rustlings/commit/72aaa15e6ab4b72b3422f1c6356396e20a2a2bb8))
+* **info:**  Fix typo (#635) ([cddc1e86](https://github.com/rust-lang/rustlings/commit/cddc1e86e7ec744ee644cc774a4887b1a0ded3e8))
+* **iterators2:**  Moved errors out of tests. ([baf4ba17](https://github.com/rust-lang/rustlings/commit/baf4ba175ba6eb92989e3dd54ecbec4bedc9a863), closes [#359](https://github.com/rust-lang/rustlings/issues/359))
+* **iterators3:**  Enabled iterators3.rs to run without commented out tests. ([c6712dfc](https://github.com/rust-lang/rustlings/commit/c6712dfccd1a093e590ad22bbc4f49edc417dac0))
+* **main:**  Let find_exercise work with borrows ([347f30bd](https://github.com/rust-lang/rustlings/commit/347f30bd867343c5ace1097e085a1f7e356553f7))
+* **move_semantics4:**
+  *  Remove redundant "instead" (#640) ([cc266d7d](https://github.com/rust-lang/rustlings/commit/cc266d7d80b91e79df3f61984f231b7f1587218e))
+  *  Small readbility improvement (#617) ([10965920](https://github.com/rust-lang/rustlings/commit/10965920fbdf8a1efc85bed869e55a1787006404))
+* **option2:**  Rename uninformative variables (#675) ([b4de6594](https://github.com/rust-lang/rustlings/commit/b4de6594380636817d13c2677ec6f472a964cf43))
+* **quiz3:**  Force an answer to Q2 (#672) ([0d894e6f](https://github.com/rust-lang/rustlings/commit/0d894e6ff739943901e1ae8c904582e5c2f843bd))
+* **structs:**  Add 5.3 to structs/README (#652) ([6bd791f2](https://github.com/rust-lang/rustlings/commit/6bd791f2f44aa7f0ad926df767f6b1fa8f12a9a9))
+* **structs2:**  correct grammar in hint (#663) ([ebdb66c7](https://github.com/rust-lang/rustlings/commit/ebdb66c7bfb6d687a14cc511a559a222e6fc5de4))
+* **structs3:**
+  * reword heading comment (#664) ([9f3e8c2d](https://github.com/rust-lang/rustlings/commit/9f3e8c2dde645e5264c2d2200e68842b5f47bfa3))
+  *   add check to prevent naive implementation of is_international ([05a753fe](https://github.com/rust-lang/rustlings/commit/05a753fe6333d36dbee5f68c21dec04eacdc75df))
+* **threads1:**  line number correction ([7857b0a6](https://github.com/rust-lang/rustlings/commit/7857b0a689b0847f48d8c14cbd1865e3b812d5ca))
+* **try_from_into:**  use trait objects ([2e93a588](https://github.com/rust-lang/rustlings/commit/2e93a588e0abe8badb7eafafb9e7d073c2be5df8))
+
+#### Features
+
+*   Replace clap with argh ([7928122f](https://github.com/rust-lang/rustlings/commit/7928122fcef9ca7834d988b1ec8ca0687478beeb))
+*   Replace emojis when NO_EMOJI env variable present ([8d62a996](https://github.com/rust-lang/rustlings/commit/8d62a9963708dbecd9312e8bcc4b47049c72d155))
+*   Added iterators5.rs exercise. ([b29ea17e](https://github.com/rust-lang/rustlings/commit/b29ea17ea94d1862114af2cf5ced0e09c197dc35))
+* **arc1:**  Add more details to description and hint (#710) ([81be4044](https://github.com/rust-lang/rustlings/commit/81be40448777fa338ebced3b0bfc1b32d6370313))
+* **cli:**  Improve the list command with options, and then some ([8bbe4ff1](https://github.com/rust-lang/rustlings/commit/8bbe4ff1385c5c169c90cd3ff9253f9a91daaf8e))
+* **list:**
+  *  updated progress percentage ([1c6f7e4b](https://github.com/rust-lang/rustlings/commit/1c6f7e4b7b9b3bd36f4da2bb2b69c549cc8bd913))
+  *  added progress info ([c0e3daac](https://github.com/rust-lang/rustlings/commit/c0e3daacaf6850811df5bc57fa43e0f249d5cfa4))
+
+
+
 <a name="4.3.0"></a>
 ## 4.3.0 (2020-12-29)
 
diff --git a/Cargo.lock b/Cargo.lock
index fb361569..cc8ff94a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -539,7 +539,7 @@ checksum = "24d5f089152e60f62d28b835fbff2cd2e8dc0baf1ac13343bef92ab7eed84548"
 
 [[package]]
 name = "rustlings"
-version = "4.3.0"
+version = "4.4.0"
 dependencies = [
  "argh",
  "assert_cmd",
diff --git a/Cargo.toml b/Cargo.toml
index 397eb996..0a757040 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rustlings"
-version = "4.3.0"
+version = "4.4.0"
 authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com>"]
 edition = "2018"
 
diff --git a/README.md b/README.md
index e76a04dc..cf1de15a 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,7 @@ Basically: Clone the repository, checkout to the latest tag, run `cargo install`
 ```bash
 git clone https://github.com/rust-lang/rustlings
 cd rustlings
-git checkout tags/4.3.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
+git checkout tags/4.4.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
 cargo install --force --path .
 ```
 
diff --git a/src/main.rs b/src/main.rs
index bc1b71e4..a80ce88e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,7 +23,7 @@ mod run;
 mod verify;
 
 // In sync with crate version
-const VERSION: &str = "4.3.0";
+const VERSION: &str = "4.4.0";
 
 #[derive(FromArgs, PartialEq, Debug)]
 /// Rustlings is a collection of small exercises to get you used to writing and reading Rust code

From c6b7ad8878d77202cd1f363a0d6b021ee48604ad Mon Sep 17 00:00:00 2001
From: Dan Stoian <danmihaistoian@gmail.com>
Date: Sat, 24 Apr 2021 18:32:13 +0300
Subject: [PATCH 124/126] updated README.md; specify need for admin rights

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index cf1de15a..99b9d6e0 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ This will install Rustlings and give you access to the `rustlings` command. Run
 
 ## Windows
 
-In PowerShell, set `ExecutionPolicy` to `RemoteSigned`:
+In PowerShell (Run as Administrator), set `ExecutionPolicy` to `RemoteSigned`:
 
 ```ps
 Set-ExecutionPolicy RemoteSigned

From 4f7dbbd2c31b49d0a34f28ae4d4ccf8210289754 Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sat, 24 Apr 2021 15:36:38 +0000
Subject: [PATCH 125/126] docs: update README.md [skip ci]

---
 README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 99b9d6e0..8ca25bae 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-90-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-91-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️
@@ -278,6 +278,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tr>
     <td align="center"><a href="https://github.com/hongshaoyang"><img src="https://avatars.githubusercontent.com/u/19281800?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Shao Yang Hong</b></sub></a><br /><a href="#content-hongshaoyang" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/bmacer"><img src="https://avatars.githubusercontent.com/u/13931806?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Brandon Macer</b></sub></a><br /><a href="#content-bmacer" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/stoiandan"><img src="https://avatars.githubusercontent.com/u/10388612?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Stoian Dan</b></sub></a><br /><a href="#content-stoiandan" title="Content">🖋</a></td>
   </tr>
 </table>
 

From 3a9ec4192dc7584a56999d70b533ec18a03a096c Mon Sep 17 00:00:00 2001
From: "allcontributors[bot]"
 <46447321+allcontributors[bot]@users.noreply.github.com>
Date: Sat, 24 Apr 2021 15:36:39 +0000
Subject: [PATCH 126/126] docs: update .all-contributorsrc [skip ci]

---
 .all-contributorsrc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.all-contributorsrc b/.all-contributorsrc
index 2820d18a..2f209713 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -838,6 +838,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "stoiandan",
+      "name": "Stoian Dan",
+      "avatar_url": "https://avatars.githubusercontent.com/u/10388612?v=4",
+      "profile": "https://github.com/stoiandan",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,