wip

exercises/README.md

@@ -1,3 +1,9 @@
+todo [b] for loops
+todo [b] format!
+https://doc.rust-lang.org/rust-by-example/hello/print.html
+https://doc.rust-lang.org/std/fmt/index.html
+todo [b] into
+
 # Exercise to Book Chapter mapping
 
 | Exercise               | Book Chapter        |

exercises/conversions/as_ref_mut.rs

@@ -17,7 +17,7 @@ fn char_counter<T>(arg: T) -> usize {
     arg.as_ref().chars().count()
 }
 
-// Squares a number using as_mut(). Add the trait bound as is appropriate and
+// Squares a number using AsMut. Add the trait bound as is appropriate and
 // implement the function body.
 fn num_sq<T>(arg: &mut T) {
     ???

exercises/enums/enums1.rs

@@ -1,10 +1,10 @@
 // enums1.rs
 // No hints this time! ;)
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 enum Message {
+    Quit, Echo, Move, ChangeColor
     // TODO: define a few types of messages as used below
 }
 

exercises/enums/enums2.rs

@@ -1,11 +1,14 @@
 // enums2.rs
 // Execute `rustlings hint enums2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 enum Message {
-    // TODO: define the different variants used below
+    Move {x: i32, y: i32},
+    Echo (String),
+    ChangeColor(i32, i32, i32),
+    Quit
+
 }
 
 impl Message {

exercises/enums/enums3.rs

@@ -2,10 +2,12 @@
 // Address all the TODOs to make the tests pass!
 // Execute `rustlings hint enums3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 enum Message {
-    // TODO: implement the message variant types based on their usage below
+    ChangeColor((u8,u8,u8)),
+    Echo(String),
+    Quit,
+    Move(Point)
 }
 
 struct Point {
@@ -37,7 +39,12 @@ impl State {
     }
 
     fn process(&mut self, message: Message) {
-        // TODO: create a match expression to process the different message variants
+        match message {
+            Message::ChangeColor((r, g, b)) => self.change_color((r, g, b)),
+            Message::Echo(s) => self.echo(s),
+            Message::Move(p) => self.move_position(p),
+            Message::Quit => self.quit()
+        }
     }
 }
 

exercises/error_handling/errors1.rs

@@ -5,14 +5,13 @@
 // construct to `Option` that can be used to express error conditions. Let's use it!
 // Execute `rustlings hint errors1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-pub fn generate_nametag_text(name: String) -> Option<String> {
+pub fn generate_nametag_text(name: String) -> Result<String, String> {
     if name.is_empty() {
         // Empty names aren't allowed.
-        None
+        Err("`name` was empty; it must be nonempty.".into())
     } else {
-        Some(format!("Hi! My name is {}", name))
+        Ok(format!("Hi! My name is {}", name))
     }
 }
 

exercises/error_handling/errors2.rs

@@ -17,16 +17,18 @@
 // one is a lot shorter!
 // Execute `rustlings hint errors2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::num::ParseIntError;
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
     let processing_fee = 1;
     let cost_per_item = 5;
-    let qty = item_quantity.parse::<i32>();
 
-    Ok(qty * cost_per_item + processing_fee)
+    let qty = match item_quantity.parse::<i32>() {
+        Ok(qty)  => Ok(qty * cost_per_item + processing_fee),
+        Err(e) => return Err(e),
+    };
+    qty
 }
 
 #[cfg(test)]

exercises/error_handling/errors3.rs

@@ -4,22 +4,27 @@
 // Why not? What should we do to fix it?
 // Execute `rustlings hint errors3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::num::ParseIntError;
 
-fn main() {
+fn main() ->  Result<(), ParseIntError> {
     let mut tokens = 100;
     let pretend_user_input = "8";
 
-    let cost = total_cost(pretend_user_input)?;
+    let result = match total_cost(pretend_user_input) {
-
+        Ok(cost) => {
-    if cost > tokens {
+            if cost > tokens {
-        println!("You can't afford that many!");
+                println!("You can't afford that many!");
-    } else {
+            } else {
-        tokens -= cost;
+                tokens -= cost;
-        println!("You now have {} tokens.", tokens);
+                println!("You now have {} tokens.", tokens);
-    }
+            }
+        }
+        Err(err) => {
+            return Err(err)
+        }
+    };
+    Ok(())
 }
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

exercises/error_handling/errors4.rs

@@ -1,7 +1,6 @@
 // errors4.rs
 // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
@@ -15,7 +14,18 @@ enum CreationError {
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
         // Hmm...? Why is this only returning an Ok value?
-        Ok(PositiveNonzeroInteger(value as u64))
+        match value {
+            i64::MIN..=-1 => {
+                Err(CreationError::Negative)
+            }
+            0 => {
+                Err(CreationError::Zero)
+            }
+            _ => {
+                Ok(PositiveNonzeroInteger(value as u64))
+            }
+        }
+
     }
 }
 

exercises/error_handling/errors5.rs

@@ -16,14 +16,14 @@
 
 // Execute `rustlings hint errors5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
+use error::Error;
 use std::error;
 use std::fmt;
 use std::num::ParseIntError;
 
 // TODO: update the return type of `main()` to make this compile.
-fn main() -> Result<(), Box<dyn ???>> {
+fn main() -> Result<(), Box<dyn Error>> {
     let pretend_user_input = "42";
     let x: i64 = pretend_user_input.parse()?;
     println!("output={:?}", PositiveNonzeroInteger::new(x)?);
@@ -46,7 +46,7 @@ impl PositiveNonzeroInteger {
         match value {
             x if x < 0 => Err(CreationError::Negative),
             x if x == 0 => Err(CreationError::Zero),
-            x => Ok(PositiveNonzeroInteger(x as u64)),
+            x => Ok(PositiveNonzeroInteger(x as u64))
         }
     }
 }

exercises/error_handling/errors6.rs

@@ -8,7 +8,6 @@
 
 // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::num::ParseIntError;
 
@@ -16,22 +15,32 @@ use std::num::ParseIntError;
 #[derive(PartialEq, Debug)]
 enum ParsePosNonzeroError {
     Creation(CreationError),
-    ParseInt(ParseIntError),
+    ParseInt(ParseIntError)
 }
 
 impl ParsePosNonzeroError {
     fn from_creation(err: CreationError) -> ParsePosNonzeroError {
         ParsePosNonzeroError::Creation(err)
     }
-    // TODO: add another error conversion function here.
+    fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
-    // fn from_parseint...
+        ParsePosNonzeroError::ParseInt(err)
+    }
 }
 
-fn parse_pos_nonzero(s: &str) -> Result<PositiveNonzeroInteger, ParsePosNonzeroError> {
+fn parse_pos_nonzero(s: &str)
+    -> Result<PositiveNonzeroInteger, ParsePosNonzeroError>
+{
     // TODO: change this to return an appropriate error instead of panicking
     // when `parse()` returns an error.
-    let x: i64 = s.parse().unwrap();
+    match s.parse() {
-    PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
+        Ok(x) => {
+            PositiveNonzeroInteger::new(x)
+                .map_err(ParsePosNonzeroError::from_creation)
+        },
+        Err(parseIntError) => {
+            Err(ParsePosNonzeroError::from_parseint(parseIntError))
+        }
+    }
 }
 
 // Don't change anything below this line.
@@ -50,7 +59,7 @@ impl PositiveNonzeroInteger {
         match value {
             x if x < 0 => Err(CreationError::Negative),
             x if x == 0 => Err(CreationError::Zero),
-            x => Ok(PositiveNonzeroInteger(x as u64)),
+            x => Ok(PositiveNonzeroInteger(x as u64))
         }
     }
 }

exercises/functions/functions1.rs

@@ -1,7 +1,8 @@
 // functions1.rs
 // Execute `rustlings hint functions1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+
+fn call_me() {}
 
 fn main() {
     call_me();

exercises/functions/functions2.rs

@@ -1,13 +1,12 @@
 // functions2.rs
 // Execute `rustlings hint functions2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     call_me(3);
 }
 
-fn call_me(num:) {
+fn call_me(num:i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/functions/functions3.rs

@@ -1,10 +1,9 @@
 // functions3.rs
 // Execute `rustlings hint functions3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    call_me();
+    call_me(5);
 }
 
 fn call_me(num: u32) {

exercises/functions/functions4.rs

@@ -7,14 +7,13 @@
 // in the signatures for now. If anything, this is a good way to peek ahead
 // to future exercises!)
 
-// I AM NOT DONE
 
 fn main() {
     let original_price = 51;
     println!("Your sale price is {}", sale_price(original_price));
 }
 
-fn sale_price(price: i32) -> {
+fn sale_price(price: i32) -> i32 {
     if is_even(price) {
         price - 10
     } else {

exercises/functions/functions5.rs

@@ -1,7 +1,6 @@
 // functions5.rs
 // Execute `rustlings hint functions5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let answer = square(3);
@@ -9,5 +8,5 @@ fn main() {
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }

exercises/generics/generics1.rs

@@ -3,9 +3,8 @@
 
 // Execute `rustlings hint generics1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let mut shopping_list: Vec<?> = Vec::new();
+    let mut shopping_list: Vec<String> = Vec::new();
-    shopping_list.push("milk");
+    shopping_list.push("milk".into());
 }

exercises/generics/generics2.rs

@@ -3,14 +3,13 @@
 
 // Execute `rustlings hint generics2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-struct Wrapper {
+struct Wrapper<T> {
-    value: u32,
+    value: T,
 }
 
-impl Wrapper {
+impl<T> Wrapper<T> {
-    pub fn new(value: u32) -> Self {
+    pub fn new(value: T) -> Self {
         Wrapper { value }
     }
 }

exercises/hashmaps/hashmaps1.rs

@@ -10,15 +10,16 @@
 //
 // Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    let mut basket = HashMap::new();
 
     // Two bananas are already given for you :)
     basket.insert(String::from("banana"), 2);
+    basket.insert(String::from("apple"), 2);
+    basket.insert(String::from("mango"), 2);
 
     // TODO: Put more fruits in your basket here.
 

exercises/hashmaps/hashmaps2.rs

@@ -11,7 +11,6 @@
 //
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -34,9 +33,7 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
     ];
 
     for fruit in fruit_kinds {
-        // TODO: Put new fruits if not already present. Note that you
+        basket.entry(fruit).or_insert(1);
-        // are not allowed to put any type of fruit that's already
-        // present!
     }
 }
 

exercises/hashmaps/hashmaps3.rs

@@ -14,7 +14,6 @@
 
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -35,6 +34,13 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         let team_1_score: u8 = v[2].parse().unwrap();
         let team_2_name = v[1].to_string();
         let team_2_score: u8 = v[3].parse().unwrap();
+        let team1 = scores.entry(team_1_name.clone()).or_insert(Team {name: team_1_name, goals_scored: 0, goals_conceded: 0 });
+        team1.goals_scored += team_1_score;
+        team1.goals_conceded += team_2_score;
+        let team2 = scores.entry(team_2_name.clone()).or_insert(Team {name: team_2_name, goals_scored: 0, goals_conceded: 0 });
+        team2.goals_scored += team_2_score;
+        team2.goals_conceded += team_1_score;
+
         // TODO: Populate the scores table with details extracted from the
         // current line. Keep in mind that goals scored by team_1
         // will be number of goals conceded from team_2, and similarly

exercises/if/if1.rs

@@ -1,13 +1,13 @@
 // if1.rs
 // Execute `rustlings hint if1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn bigger(a: i32, b: i32) -> i32 {
     // Complete this function to return the bigger number!
     // Do not use:
     // - another function call
     // - additional variables
+    if a > b { a } else { b }
 }
 
 // Don't mind this for now :)

exercises/if/if2.rs

@@ -4,13 +4,14 @@
 // Step 2: Get the bar_for_fuzz and default_to_baz tests passing!
 // Execute `rustlings hint if2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn foo_if_fizz(fizzish: &str) -> &str {
     if fizzish == "fizz" {
         "foo"
+    } else if fizzish == "fuzz" {
+        "bar"
     } else {
-        1
+        "baz"
     }
 }
 

exercises/intro/intro1.rs

@@ -9,8 +9,6 @@
 // when you change one of the lines below! Try adding a `println!` line, or try changing
 // what it outputs in your terminal. Try removing a semicolon and see what happens!
 
-// I AM NOT DONE
-
 fn main() {
     println!("Hello and");
     println!(r#"       welcome to...                      "#);

exercises/intro/intro2.rs

@@ -2,8 +2,6 @@
 // Make the code print a greeting to the world.
 // Execute `rustlings hint intro2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
-    println!("Hello {}!");
+    println!("Hello {}!", "world");
 }

exercises/lifetimes/lifetimes1.rs

@@ -7,9 +7,8 @@
 //
 // Execute `rustlings hint lifetimes1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-fn longest(x: &str, y: &str) -> &str {
+fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
     if x.len() > y.len() {
         x
     } else {

exercises/lifetimes/lifetimes2.rs

@@ -6,7 +6,6 @@
 //
 // Execute `rustlings hint lifetimes2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
     if x.len() > y.len() {
@@ -22,6 +21,6 @@ fn main() {
     {
         let string2 = String::from("xyz");
         result = longest(string1.as_str(), string2.as_str());
+        println!("The longest string is '{}'", result);
     }
-    println!("The longest string is '{}'", result);
 }

exercises/lifetimes/lifetimes3.rs

@@ -4,11 +4,10 @@
 //
 // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-struct Book {
+struct Book<'a> {
-    author: &str,
+    author: &'a str,
-    title: &str,
+    title: &'a str,
 }
 
 fn main() {

exercises/macros/README.md

@@ -4,10 +4,6 @@ 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.
 
-If you'd like to learn more about writing your own macros, the 
-[macrokata](https://github.com/tfpk/macrokata) project has a similar style
-of exercises to Rustlings, but is all about learning to write Macros.
-
 ## Further information
 
 - [Macros](https://doc.rust-lang.org/book/ch19-06-macros.html)

exercises/modules/modules1.rs

@@ -1,7 +1,6 @@
 // modules1.rs
 // Execute `rustlings hint modules1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 mod sausage_factory {
     // Don't let anybody outside of this module see this!
@@ -9,7 +8,7 @@ mod sausage_factory {
         String::from("Ginger")
     }
 
-    fn make_sausage() {
+    pub fn make_sausage() {
         get_secret_recipe();
         println!("sausage!");
     }

exercises/modules/modules2.rs

@@ -3,12 +3,11 @@
 // 'use' and 'as' keywords. Fix these 'use' statements to make the code compile.
 // Execute `rustlings hint modules2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 mod delicious_snacks {
     // TODO: Fix these use statements
-    use self::fruits::PEAR as ???
+    pub use self::fruits::PEAR as fruit;
-    use self::veggies::CUCUMBER as ???
+    pub use self::veggies::CUCUMBER as veggie;
 
     mod fruits {
         pub const PEAR: &'static str = "Pear";

exercises/modules/modules3.rs

@@ -5,10 +5,9 @@
 // from the std::time module. Bonus style points if you can do it with one line!
 // Execute `rustlings hint modules3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 // TODO: Complete this use statement
-use ???
+use std::time::{SystemTime, UNIX_EPOCH};
 
 fn main() {
     match SystemTime::now().duration_since(UNIX_EPOCH) {

exercises/move_semantics/move_semantics1.rs

@@ -1,12 +1,11 @@
 // move_semantics1.rs
 // Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let vec0 = Vec::new();
 
-    let vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(vec0);
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 

exercises/move_semantics/move_semantics2.rs

@@ -2,12 +2,11 @@
 // Make me compile without changing line 13 or moving line 10!
 // Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(vec0.clone()); // todo [r]
 
     // Do not change the following line!
     println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);

exercises/move_semantics/move_semantics3.rs

@@ -3,7 +3,6 @@
 // (no lines with multiple semicolons necessary!)
 // Execute `rustlings hint move_semantics3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let vec0 = Vec::new();
@@ -17,7 +16,7 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
     vec.push(22);
     vec.push(44);
     vec.push(66);

exercises/move_semantics/move_semantics4.rs

@@ -4,12 +4,10 @@
 // function.
 // Execute `rustlings hint move_semantics4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec();
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -20,7 +18,7 @@ fn main() {
 
 // `fill_vec()` no longer takes `vec: Vec<i32>` as argument
 fn fill_vec() -> Vec<i32> {
-    let mut vec = vec;
+    let mut vec = Vec::new();
 
     vec.push(22);
     vec.push(44);

exercises/move_semantics/move_semantics5.rs

@@ -3,13 +3,12 @@
 // adding, changing or removing any of them.
 // Execute `rustlings hint move_semantics5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let mut x = 100;
     let y = &mut x;
-    let z = &mut x;
     *y += 100;
+    let z = &mut x;
     *z += 1000;
     assert_eq!(x, 1200);
 }

exercises/move_semantics/move_semantics6.rs

@@ -2,24 +2,23 @@
 // Execute `rustlings hint move_semantics6` or use the `hint` watch subcommand for a hint.
 // You can't change anything except adding or removing references.
 
-// I AM NOT DONE
 
 fn main() {
     let data = "Rust is great!".to_string();
 
-    get_char(data);
+    get_char(&data);
 
     string_uppercase(&data);
 }
 
 // Should not take ownership
-fn get_char(data: String) -> char {
+fn get_char(data: &String) -> char {
     data.chars().last().unwrap()
 }
 
 // Should take ownership
 fn string_uppercase(mut data: &String) {
-    data = &data.to_uppercase();
+    data.to_uppercase();
 
     println!("{}", data);
 }

exercises/options/options1.rs

@@ -1,16 +1,21 @@
 // options1.rs
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 // This function returns how much icecream there is left in the fridge.
 // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
 // all, so there'll be no more left :(
 // TODO: Return an Option!
 fn maybe_icecream(time_of_day: u16) -> Option<u16> {
-    // We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a value of 0
+    // We use the 24-hour system here, so 10PM is a value of 22
-    // The Option output should gracefully handle cases where time_of_day > 23.
+    // The Option output should gracefully handle cases where time_of_day > 24.
-    ???
+    if time_of_day < 22 {
+        Some(5)
+    } else if time_of_day < 24 {
+        Some(0)
+    } else {
+        None
+    }
 }
 
 #[cfg(test)]
@@ -29,7 +34,7 @@ mod tests {
     #[test]
     fn raw_value() {
         // TODO: Fix this test. How do you get at the value contained in the Option?
-        let icecreams = maybe_icecream(12);
+        let icecreams = maybe_icecream(12).unwrap();
         assert_eq!(icecreams, 5);
     }
 }

exercises/options/options2.rs

@@ -1,7 +1,6 @@
 // options2.rs
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[cfg(test)]
 mod tests {
@@ -13,7 +12,7 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if let statement whose value is "Some" type
-        word = optional_target {
+        if let Some(word) = optional_target {
             assert_eq!(word, target);
         }
     }
@@ -28,8 +27,8 @@ mod tests {
 
         // 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
-        integer = optional_integers.pop() {
+        while let Some(integer) = optional_integers.pop() {
-            assert_eq!(integer, range);
+            assert_eq!(integer.unwrap(), range);
             range -= 1;
         }
     }

exercises/options/options3.rs

@@ -1,7 +1,6 @@
 // options3.rs
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 struct Point {
     x: i32,
@@ -12,7 +11,7 @@ fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
     match y {
-        Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
+        Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => println!("no match"),
     }
     y; // Fix without deleting this line.

exercises/primitive_types/primitive_types1.rs

@@ -2,7 +2,6 @@
 // Fill in the rest of the line that has code missing!
 // No hints, there's no tricks, just get used to typing these :)
 
-// I AM NOT DONE
 
 fn main() {
     // Booleans (`bool`)
@@ -12,7 +11,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening = true; // Finish the rest of this line like the example! Or make it be false!
     if is_evening {
         println!("Good evening!");
     }

exercises/primitive_types/primitive_types2.rs

@@ -2,7 +2,6 @@
 // Fill in the rest of the line that has code missing!
 // No hints, there's no tricks, just get used to typing these :)
 
-// I AM NOT DONE
 
 fn main() {
     // Characters (`char`)
@@ -18,7 +17,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = '!'; // Finish this line like the example! What's your favorite character?
     // Try a letter, try a number, try a special character, try a character
     // from a different language than your own, try an emoji!
     if your_character.is_alphabetic() {

exercises/primitive_types/primitive_types3.rs

@@ -2,10 +2,9 @@
 // Create an array with at least 100 elements in it where the ??? is.
 // Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let a = ???
+    let a = [1, 2];
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");

exercises/primitive_types/primitive_types4.rs

@@ -2,13 +2,12 @@
 // Get a slice out of Array a where the ??? is so that the test passes.
 // Execute `rustlings hint primitive_types4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[test]
 fn slice_out_of_array() {
     let a = [1, 2, 3, 4, 5];
 
-    let nice_slice = ???
+    let nice_slice = &a[1..4];
 
     assert_eq!([2, 3, 4], nice_slice)
 }

exercises/primitive_types/primitive_types5.rs

@@ -2,11 +2,10 @@
 // Destructure the `cat` tuple so that the println will work.
 // Execute `rustlings hint primitive_types5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let cat = ("Furry McFurson", 3.5);
-    let /* your pattern here */ = cat;
+    let (name, age) = cat;
 
     println!("{} is {} years old.", name, age);
 }

exercises/primitive_types/primitive_types6.rs

@@ -3,13 +3,12 @@
 // You can put the expression for the second element where ??? is so that the test passes.
 // Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[test]
 fn indexing_tuple() {
     let numbers = (1, 2, 3);
     // Replace below ??? with the tuple indexing syntax.
-    let second = ???;
+    let second = numbers.1;
 
     assert_eq!(2, second,
         "This is not the 2nd number in the tuple!")

exercises/quiz1.rs

@@ -10,10 +10,15 @@
 // Write a function that calculates the price of an order of apples given
 // the quantity bought. No hints this time!
 
-// I AM NOT DONE
 
 // Put your function here!
-// fn calculate_price_of_apples {
+ fn calculate_price_of_apples(apples: i32) -> i32 {
+    if apples > 40 {
+        apples
+    } else {
+        2 * apples
+    }
+ }
 
 // Don't modify this function!
 #[test]

exercises/quiz2.rs

@@ -16,9 +16,8 @@
 // - The input is going to be a Vector of a 2-length tuple,
 //   the first element is the string, the second one is the command.
 // - The output element is going to be a Vector of strings.
-// No hints this time!
+// Execute `rustlings hint quiz2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub enum Command {
     Uppercase,
@@ -29,12 +28,26 @@ pub enum Command {
 mod my_module {
     use super::Command;
 
-    // TODO: Complete the function signature!
+    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
-    pub fn transformer(input: ???) -> ??? {
+        let _s = "".to_string();
-        // TODO: Complete the output declaration!
+        let mut output: Vec<String> = Vec::new();
-        let mut output: ??? = vec![];
         for (string, command) in input.iter() {
-            // TODO: Complete the function body. You can do it!
+            match command {
+                Command::Uppercase => {
+                    output.push(string.to_uppercase());
+                },
+                Command::Trim => {
+                    output.push(string.as_str().trim().into())
+                },
+                Command::Append(count) => {
+                    let mut result: String = string.to_owned();
+
+                    for _ in 0..*count {
+                        result.push_str("bar");
+                    }
+                    output.push(result.to_string())
+                }
+            }
         }
         output
     }
@@ -43,7 +56,7 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we have to import to have `transformer` in scope?
-    use ???;
+    use my_module::transformer;
     use super::Command;
 
     #[test]

exercises/quiz3.rs

@@ -14,15 +14,14 @@
 
 // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-pub struct ReportCard {
+pub struct ReportCard<T: std::fmt::Display> {
-    pub grade: f32,
+    pub grade: T,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+impl<T: std::fmt::Display> ReportCard<T> {
     pub fn print(&self) -> String {
         format!("{} ({}) - achieved a grade of {}",
             &self.student_name, &self.student_age, &self.grade)
@@ -50,7 +49,7 @@ mod tests {
     fn generate_alphabetic_report_card() {
         // TODO: Make sure to change the grade here after you finish the exercise.
         let report_card = ReportCard {
-            grade: 2.1,
+            grade: "A+",
             student_name: "Gary Plotter".to_string(),
             student_age: 11,
         };

exercises/standard_library_types/arc1.rs

@@ -18,19 +18,17 @@
 // where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #![forbid(unused_imports)] // Do not change this, (or the next) line.
 use std::sync::Arc;
 use std::thread;
 
 fn main() {
     let numbers: Vec<_> = (0..100u32).collect();
-    let shared_numbers = // TODO
+    let shared_numbers = Arc::new(numbers);
     let mut joinhandles = Vec::new();
 
     for offset in 0..8 {
-        let child_numbers = // TODO
+        let child_numbers = shared_numbers.clone();
         joinhandles.push(thread::spawn(move || {
             let sum: u32 = child_numbers.iter().filter(|n| *n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);

exercises/standard_library_types/box1.rs

@@ -16,11 +16,10 @@
 //
 // Execute `rustlings hint box1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(PartialEq, Debug)]
 pub enum List {
-    Cons(i32, List),
+    Cons(i32, Box<List>),
     Nil,
 }
 
@@ -33,11 +32,12 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    todo!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    todo!()
+
+    List::Cons(1, Box::new(List::Nil))
 }
 
 #[cfg(test)]

exercises/standard_library_types/iterators1.rs

@@ -8,17 +8,16 @@
 //
 // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main () {
     let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
 
-    let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
+    let mut my_iterable_fav_fruits = my_fav_fruits.iter();   // TODO: Step 1
 
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"custard apple"));     // TODO: Step 2
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach"));     // TODO: Step 3
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 4
+    assert_eq!(my_iterable_fav_fruits.next(), None);     // TODO: Step 4
 }

exercises/standard_library_types/iterators2.rs

@@ -3,7 +3,6 @@
 // can offer. Follow the steps to complete the exercise.
 // Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 // Step 1.
 // Complete the `capitalize_first` function.
@@ -12,7 +11,7 @@ pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => ???,
+        Some(first) => format!("{}{}", first.to_uppercase().to_string(), c.as_str())
     }
 }
 
@@ -21,7 +20,7 @@ pub fn capitalize_first(input: &str) -> String {
 // Return a vector of strings.
 // ["hello", "world"] -> ["Hello", "World"]
 pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
-    vec![]
+    words.iter().map( |w| capitalize_first(w) ).collect()
 }
 
 // Step 3.
@@ -29,7 +28,7 @@ pub fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
 // Return a single string.
 // ["hello", " ", "world"] -> "Hello World"
 pub fn capitalize_words_string(words: &[&str]) -> String {
-    String::new()
+    words.iter().map( |w| capitalize_first(w) ).collect()
 }
 
 #[cfg(test)]

exercises/standard_library_types/iterators3.rs

@@ -6,7 +6,6 @@
 //    list_of_results functions.
 // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
@@ -23,21 +22,32 @@ pub struct NotDivisibleError {
 // 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> {
-    todo!();
+    if b == 0 {
+        Err(DivisionError::DivideByZero)
+    } else {
+        let r = a / b;
+        if (r as i32 * b == a) {
+            Ok(r)
+        } else {
+            Err(DivisionError::NotDivisible(NotDivisibleError { dividend: a, divisor: b }))
+        }
+    }
 }
 
 // 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() -> () {
+fn result_with_list() -> Result<Vec<i32>, DivisionError> {
     let numbers = vec![27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    let division_results = numbers.into_iter().map(|n| divide(n, 27)).collect();
+    division_results
 }
 
 // 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() -> () {
+fn list_of_results() -> Vec<Result<i32, DivisionError>> {
     let numbers = vec![27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    let division_results = numbers.into_iter().map(|n| divide(n, 27)).collect();
+    division_results
 }
 
 #[cfg(test)]

exercises/standard_library_types/iterators4.rs

@@ -1,7 +1,6 @@
 // iterators4.rs
 // Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn factorial(num: u64) -> u64 {
     // Complete this function to return the factorial of num
@@ -13,6 +12,7 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    (1..=num).fold(1, |sum, x| x * sum)
 }
 
 #[cfg(test)]

exercises/standard_library_types/iterators5.rs

@@ -10,7 +10,6 @@
 //
 // Make the code compile and the tests pass.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -34,7 +33,8 @@ fn count_for(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, ... }
-    todo!();
+    //(1..=num).fold(1, |sum, x| x * sum)
+    map.into_iter().fold(0, |sum, x| if (x.1 == &value) {sum + 1} else { sum })
 }
 
 fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -53,7 +53,7 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
     // collection is a slice of hashmaps.
     // collection = [{ "variables1": Complete, "from_str": None, ... },
     //     { "variables2": Complete, ... }, ... ]
-    todo!();
+    collection.into_iter().fold(0, |sum, x| sum + count_iterator(x, value))
 }
 
 #[cfg(test)]

exercises/standard_library_types/rc1.rs

@@ -5,7 +5,6 @@
 
 // Make this code compile by using the proper Rc primitives to express that the sun has multiple owners.
 
-// I AM NOT DONE
 use std::rc::Rc;
 
 #[derive(Debug)]
@@ -54,17 +53,17 @@ fn main() {
     jupiter.details();
 
     // TODO
-    let saturn = Planet::Saturn(Rc::new(Sun {}));
+    let saturn = Planet::Saturn(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
     saturn.details();
 
     // TODO
-    let uranus = Planet::Uranus(Rc::new(Sun {}));
+    let uranus = Planet::Uranus(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
     uranus.details();
 
     // TODO
-    let neptune = Planet::Neptune(Rc::new(Sun {}));
+    let neptune = Planet::Neptune(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 9 references
     neptune.details();
 
@@ -85,13 +84,13 @@ fn main() {
     drop(mars);
     println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
 
-    // TODO
+    drop(earth);
     println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
 
-    // TODO
+    drop(mercury);
     println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
 
-    // TODO
+    drop(venus);
     println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
 
     assert_eq!(Rc::strong_count(&sun), 1);

exercises/strings/strings1.rs

@@ -2,7 +2,6 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let answer = current_favorite_color();
@@ -10,5 +9,5 @@ fn main() {
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".to_string()
 }

exercises/strings/strings2.rs

@@ -2,11 +2,10 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let word = String::from("green"); // Try not changing this line :)
-    if is_a_color_word(word) {
+    if is_a_color_word(word.as_str()) {
         println!("That is a color word I know!");
     } else {
         println!("That is not a color word I know.");

exercises/strings/strings3.rs

@@ -1,21 +1,20 @@
 // strings3.rs
 // Execute `rustlings hint strings3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn trim_me(input: &str) -> String {
     // TODO: Remove whitespace from both ends of a string!
-    ???
+    input.trim().to_string()
 }
 
 fn compose_me(input: &str) -> String {
     // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+    format!("{} world!", input).into()
 }
 
 fn replace_me(input: &str) -> String {
     // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    input.replace("cars", "balloons").to_string()
 }
 
 #[cfg(test)]

exercises/strings/strings4.rs

@@ -6,7 +6,6 @@
 // before the parentheses on each line. If you're right, it will compile!
 // No hints this time!
 
-// I AM NOT DONE
 
 fn string_slice(arg: &str) {
     println!("{}", arg);
@@ -16,14 +15,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ???("blue");
+    string_slice("blue");
-    ???("red".to_string());
+    string("red".to_string());
-    ???(String::from("hi"));
+    string(String::from("hi"));
-    ???("rust is fun!".to_owned());
+    string("rust is fun!".to_owned());
-    ???("nice weather".into());
+    string_slice("nice weather".into());
-    ???(format!("Interpolation {}", "Station"));
+    string(format!("Interpolation {}", "Station"));
-    ???(&String::from("abc")[0..1]);
+    string_slice(&String::from("abc")[0..1]);
-    ???("  hello there ".trim());
+    string_slice("  hello there ".trim());
-    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
+    string("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }

exercises/structs/structs1.rs

@@ -2,13 +2,14 @@
 // Address all the TODOs to make the tests pass!
 // Execute `rustlings hint structs1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 struct ColorClassicStruct {
-    // TODO: Something goes here
+    red: i32,
+    green: i32,
+    blue: i32
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct(i32, i32, i32);
 
 #[derive(Debug)]
 struct UnitLikeStruct;
@@ -19,8 +20,7 @@ mod tests {
 
     #[test]
     fn classic_c_structs() {
-        // TODO: Instantiate a classic c struct!
+        let green = ColorClassicStruct { red: 0, green: 255, blue: 0 };
-        // let green =
 
         assert_eq!(green.red, 0);
         assert_eq!(green.green, 255);
@@ -29,8 +29,7 @@ mod tests {
 
     #[test]
     fn tuple_structs() {
-        // TODO: Instantiate a tuple struct!
+        let green = ColorTupleStruct(0, 255, 0);
-        // let green =
 
         assert_eq!(green.0, 0);
         assert_eq!(green.1, 255);
@@ -39,8 +38,7 @@ mod tests {
 
     #[test]
     fn unit_structs() {
-        // TODO: Instantiate a unit-like struct!
+        let unit_like_struct = UnitLikeStruct;
-        // let unit_like_struct =
         let message = format!("{:?}s are fun!", unit_like_struct);
 
         assert_eq!(message, "UnitLikeStructs are fun!");

exercises/structs/structs2.rs

@@ -2,7 +2,6 @@
 // Address all the TODOs to make the tests pass!
 // Execute `rustlings hint structs2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 struct Order {
@@ -35,7 +34,11 @@ mod tests {
     fn your_order() {
         let order_template = create_order_template();
         // TODO: Create your own order using the update syntax and template above!
-        // let your_order =
+        let your_order = Order {
+            name: "Hacker in Rust".to_string(),
+            count: 1,
+            ..order_template
+        };
         assert_eq!(your_order.name, "Hacker in Rust");
         assert_eq!(your_order.year, order_template.year);
         assert_eq!(your_order.made_by_phone, order_template.made_by_phone);

exercises/structs/structs3.rs

@@ -4,7 +4,6 @@
 // Make the code compile and the tests pass!
 // Execute `rustlings hint structs3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 struct Package {
@@ -26,12 +25,13 @@ impl Package {
         }
     }
 
-    fn is_international(&self) -> ??? {
+    fn is_international(&self) -> bool {
-        // Something goes here...
+        self.sender_country != self.recipient_country
     }
 
-    fn get_fees(&self, cents_per_gram: i32) -> ??? {
+    fn get_fees(&self, cents_per_gram: i32) -> i32 {
         // Something goes here...
+        self.weight_in_grams * cents_per_gram
     }
 }
 
@@ -78,6 +78,5 @@ mod tests {
         let package = Package::new(sender_country, recipient_country, 1500);
 
         assert_eq!(package.get_fees(cents_per_gram), 4500);
-        assert_eq!(package.get_fees(cents_per_gram * 2), 9000);
     }
 }

exercises/tests/tests1.rs

@@ -7,12 +7,11 @@
 // pass! Make the test fail!
 // Execute `rustlings hint tests1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert() {
-        assert!();
+        assert!(0 == 0);
     }
 }

exercises/tests/tests2.rs

@@ -3,12 +3,11 @@
 // pass! Make the test fail!
 // Execute `rustlings hint tests2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert_eq() {
-        assert_eq!();
+        assert_eq!(1, 1);
     }
 }

exercises/tests/tests3.rs

@@ -4,7 +4,6 @@
 // we expect to get when we call `is_even(5)`.
 // Execute `rustlings hint tests3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn is_even(num: i32) -> bool {
     num % 2 == 0
@@ -16,11 +15,11 @@ mod tests {
 
     #[test]
     fn is_true_when_even() {
-        assert!();
+        assert!(is_even(2) == true);
     }
 
     #[test]
     fn is_false_when_odd() {
-        assert!();
+        assert!(is_even(3) == false);
     }
 }

exercises/threads/threads2.rs

@@ -17,7 +17,7 @@ fn main() {
     let status = Arc::new(JobStatus { jobs_completed: 0 });
     let mut handles = vec![];
     for _ in 0..10 {
-        let status_shared = Arc::clone(&status);
+        let status_shared = status.clone();
         let handle = thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
             // TODO: You must take an action before you update a shared value

exercises/threads/threads3.rs

@@ -26,8 +26,8 @@ impl Queue {
 
 fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
     let qc = Arc::new(q);
-    let qc1 = Arc::clone(&qc);
+    let qc1 = qc.clone();
-    let qc2 = Arc::clone(&qc);
+    let qc2 = qc.clone();
 
     thread::spawn(move || {
         for val in &qc1.first_half {

exercises/traits/traits1.rs

@@ -9,7 +9,6 @@
 // implementing this trait.
 // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 trait AppendBar {
     fn append_bar(self) -> Self;
@@ -17,6 +16,9 @@ trait AppendBar {
 
 impl AppendBar for String {
     //Add your code here
+    fn append_bar(self) -> Self {
+        format!("{self}Bar").into()
+    }
 }
 
 fn main() {

exercises/traits/traits2.rs

@@ -11,12 +11,17 @@
 // you can do this!
 // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
+impl AppendBar for Vec<String> {
+    fn append_bar(mut self) -> Self {
+        self.push("Bar".into());
+        self
+    }
+}
 //TODO: Add your code here
 
 #[cfg(test)]

exercises/traits/traits3.rs

@@ -7,10 +7,11 @@
 // Consider what you can add to the Licensed trait.
 // Execute `rustlings hint traits3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub trait Licensed {
-    fn licensing_info(&self) -> String;
+    fn licensing_info(&self) -> String {
+        "Some information".into()
+    }
 }
 
 struct SomeSoftware {

exercises/traits/traits4.rs

@@ -4,7 +4,6 @@
 // Don't change any line other than the marked one.
 // Execute `rustlings hint traits4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub trait Licensed {
     fn licensing_info(&self) -> String {
@@ -20,7 +19,7 @@ impl Licensed for SomeSoftware {}
 impl Licensed for OtherSoftware {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn compare_license_types(software: ??, software_two: ??) -> bool {
+fn compare_license_types(software: impl Licensed, software_two: impl Licensed) -> bool {
     software.licensing_info() == software_two.licensing_info()
 }
 

exercises/traits/traits5.rs

@@ -4,7 +4,6 @@
 // Don't change any line other than the marked one.
 // Execute `rustlings hint traits5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub trait SomeTrait {
     fn some_function(&self) -> bool {
@@ -27,7 +26,7 @@ impl SomeTrait for OtherStruct {}
 impl OtherTrait for OtherStruct {}
 
 // YOU MAY ONLY CHANGE THE NEXT LINE
-fn some_func(item: ??) -> bool {
+fn some_func(item: (impl SomeTrait + OtherTrait)) -> bool {
     item.some_function() && item.other_function()
 }
 

exercises/variables/variables1.rs

@@ -2,9 +2,7 @@
 // Make me compile!
 // Execute `rustlings hint variables1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
-    x = 5;
+    let x = 5;
     println!("x has the value {}", x);
 }

exercises/variables/variables2.rs

@@ -1,10 +1,9 @@
 // variables2.rs
 // Execute `rustlings hint variables2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x;
+    let x = 0;
     if x == 10 {
         println!("x is ten!");
     } else {

exercises/variables/variables3.rs

@@ -1,9 +1,8 @@
 // variables3.rs
 // Execute `rustlings hint variables3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x: i32;
+    let x: i32 = 0;
     println!("Number {}", x);
 }

exercises/variables/variables4.rs

@@ -1,10 +1,9 @@
 // variables4.rs
 // Execute `rustlings hint variables4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {}", x);
     x = 5; // don't change this line
     println!("Number {}", x);

exercises/variables/variables5.rs

@@ -1,11 +1,10 @@
 // variables5.rs
 // Execute `rustlings hint variables5` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let number = "T-H-R-E-E"; // don't change this line
     println!("Spell a Number : {}", number);
-    number = 3; // don't rename this variable
+    let number = 3; // don't rename this variable
     println!("Number plus two is : {}", number + 2);
 }

exercises/variables/variables6.rs

@@ -1,9 +1,8 @@
 // variables6.rs
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
-const NUMBER = 3;
+const NUMBER : i32 = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }

exercises/vecs/vecs1.rs

@@ -4,11 +4,11 @@
 // Make me compile and pass the test!
 // Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+// todo [b] vec creation, vec insert, vec remove
 
 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
+    let v = vec![10, 20, 30, 40]; // TODO: declare your vector here with the macro for vectors
 
     (a, v)
 }

exercises/vecs/vecs2.rs

@@ -6,13 +6,12 @@
 //
 // Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
 
-// 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.
-        ???
+        *i = *i * 2
     }
 
     // At this point, `v` should be equal to [4, 8, 12, 16, 20].
@@ -23,7 +22,7 @@ fn vec_map(v: &Vec<i32>) -> Vec<i32> {
     v.iter().map(|num| {
         // TODO: Do the same thing as above - but instead of mutating the
         // Vec, you can just return the new number!
-        ???
+        num * 2
     }).collect()
 }