added

.vscode/extensions.json

@@ -1,5 +0,0 @@
-{
-    "recommendations": [
-        "rust-lang.rust-analyzer"
-    ]
-}

exercises/enums/enums1.rs

@@ -2,11 +2,12 @@
 //
 // No hints this time! ;)
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 enum Message {
-    // TODO: define a few types of messages as used below
+    Quit,
+    Echo,
+    Move,
+    ChangeColor
 }
 
 fn main() {

exercises/enums/enums2.rs

@@ -3,11 +3,13 @@
 // 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: u8, y: u8},
+    Echo (String),
+    ChangeColor (u8, u8, u8),
+    Quit
 }
 
 impl Message {

exercises/enums/enums3.rs

@@ -5,10 +5,12 @@
 // 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
+    Move (Point),
+    Echo (String),
+    ChangeColor (u8, u8, u8),
+    Quit
 }
 
 struct Point {
@@ -45,6 +47,12 @@ impl State {
         // variants
         // Remember: When passing a tuple as a function argument, you'll need
         // extra parentheses: fn function((t, u, p, l, e))
+        match message {
+            Message::ChangeColor(r,g,b) => self.change_color((r,g,b)),
+            Message::Echo(x) => self.echo(x),
+            Message::Move(x) => self.move_position(x),
+            Message::Quit => self.quit()
+        }
     }
 }
 

exercises/error_handling/errors1.rs

@@ -9,14 +9,12 @@
 // Execute `rustlings hint errors1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
+pub fn generate_nametag_text(name: String) -> Result<String, String> {
-
-pub fn generate_nametag_text(name: String) -> Option<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

@@ -19,8 +19,6 @@
 // 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> {
@@ -28,7 +26,11 @@ pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
     let cost_per_item = 5;
     let qty = item_quantity.parse::<i32>();
 
-    Ok(qty * cost_per_item + processing_fee)
+    match qty {
+        Ok(x) => Ok(x * cost_per_item + processing_fee),
+        ParseIntError => ParseIntError
+    }
+    
 }
 
 #[cfg(test)]

exercises/error_handling/errors3.rs

@@ -7,11 +7,9 @@
 // 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";
 
@@ -22,7 +20,8 @@ fn main() {
     } else {
         tokens -= cost;
         println!("You now have {} tokens.", tokens);
-    }
+    };
+    return Ok(());
 }
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

exercises/error_handling/errors4.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
 
@@ -17,9 +15,15 @@ enum CreationError {
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
         // Hmm... Why is this always returning an Ok value?
+        if (value == 0) {
+            Err(CreationError::Zero)
+        } else if (value < 0) {
+            Err(CreationError::Negative)
+        } else {
             Ok(PositiveNonzeroInteger(value as u64))
         }
     }
+}
 
 #[test]
 fn test_creation() {

exercises/error_handling/errors5.rs

@@ -22,14 +22,12 @@
 // Execute `rustlings hint errors5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 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::Error>> {
     let pretend_user_input = "42";
     let x: i64 = pretend_user_input.parse()?;
     println!("output={:?}", PositiveNonzeroInteger::new(x)?);

exercises/error_handling/errors6.rs

@@ -9,8 +9,6 @@
 // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
 // This is a custom error type that we will be using in `parse_pos_nonzero()`.
@@ -26,15 +24,17 @@ impl ParsePosNonzeroError {
     }
     // TODO: add another error conversion function here.
     // fn from_parseint...
+    fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
+        ParsePosNonzeroError::ParseInt(err)
+    }
 }
 
 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();
+    let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parseint)?;
     PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
 }
-
 // Don't change anything below this line.
 
 #[derive(PartialEq, Debug)]

exercises/functions/functions1.rs

@@ -3,7 +3,9 @@
 // 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

@@ -3,13 +3,11 @@
 // 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

@@ -3,10 +3,8 @@
 // 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

@@ -8,14 +8,12 @@
 // Execute `rustlings hint functions4` or use the `hint` watch subcommand for a
 // hint.
 
-// 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

@@ -3,13 +3,11 @@
 // Execute `rustlings hint functions5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     let answer = square(3);
     println!("The square of 3 is {}", answer);
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }

exercises/generics/generics1.rs

@@ -6,9 +6,7 @@
 // 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<&str> = Vec::new();
     shopping_list.push("milk");
 }

exercises/generics/generics2.rs

@@ -6,14 +6,12 @@
 // Execute `rustlings hint generics2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
+struct Wrapper<T> {
-
+    value: T,
-struct Wrapper {
-    value: u32,
 }
 
-impl Wrapper {
+impl<T> Wrapper<T> {
-    pub fn new(value: u32) -> Self {
+    pub fn new(value: T) -> Self {
         Wrapper { value }
     }
 }

exercises/hashmaps/hashmaps1.rs

@@ -11,17 +11,18 @@
 // 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);
 
     // TODO: Put more fruits in your basket here.
+    basket.insert("a".to_string(), 3);
+    basket.insert("b".to_string(), 4);
+    basket.insert("c".to_string(), 5);
 
     basket
 }

exercises/hashmaps/hashmaps2.rs

@@ -14,8 +14,6 @@
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Hash, PartialEq, Eq)]
@@ -40,6 +38,11 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         // TODO: Insert new fruits if they are not already present in the
         // basket. Note that you are not allowed to put any type of fruit that's
         // already present!
+        //  You can also do: basket.entry(fruit).or_insert(10);
+        match basket.get(&fruit) {
+            Some(fruit) => {},
+            None => { basket.insert(fruit, 3); }
+        };
     }
 }
 

exercises/hashmaps/hashmaps3.rs

@@ -14,8 +14,6 @@
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 // A structure to store the goal details of a team.
@@ -24,6 +22,15 @@ struct Team {
     goals_conceded: u8,
 }
 
+fn build_or_set_team(team_name: String, scores: &mut HashMap<String, Team>, team_a_score: u8, team_b_score: u8) {
+    let team_a = scores.entry(team_name).or_insert(Team{
+        goals_scored: 0,
+        goals_conceded: 0
+    });
+    team_a.goals_scored += team_a_score;
+    team_a.goals_conceded += team_b_score;
+}
+
 fn build_scores_table(results: String) -> HashMap<String, Team> {
     // The name of the team is the key and its associated struct is the value.
     let mut scores: HashMap<String, Team> = HashMap::new();
@@ -39,6 +46,8 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         // will be the number of goals conceded from team_2, and similarly
         // goals scored by team_2 will be the number of goals conceded by
         // team_1.
+        build_or_set_team(team_1_name, &mut scores, team_1_score, team_2_score);
+        build_or_set_team(team_2_name, &mut scores, team_2_score, team_1_score);
     }
     scores
 }

exercises/if/if1.rs

@@ -2,13 +2,15 @@
 //
 // 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) {
+       return a;
+    }
+    return b;
 }
 
 // Don't mind this for now :)

exercises/if/if2.rs

@@ -5,13 +5,14 @@
 //
 // 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/if/if3.rs

@@ -2,17 +2,16 @@
 //
 // Execute `rustlings hint if3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn animal_habitat(animal: &str) -> &'static str {
     let identifier = if animal == "crab" {
         1
     } else if animal == "gopher" {
-        2.0
+        2
     } else if animal == "snake" {
         3
     } else {
-        "Unknown"
+        4
     };
 
     // DO NOT CHANGE THIS STATEMENT BELOW

exercises/intro/intro1.rs

@@ -13,8 +13,6 @@
 // Execute `rustlings hint intro1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     println!("Hello and");
     println!(r#"       welcome to...                      "#);

exercises/intro/intro2.rs

@@ -5,8 +5,6 @@
 // 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/iterators/iterators1.rs

@@ -9,18 +9,16 @@
 // Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[test]
 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/iterators/iterators2.rs

@@ -6,8 +6,6 @@
 // Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 // Step 1.
 // Complete the `capitalize_first` function.
 // "hello" -> "Hello"
@@ -15,7 +13,7 @@ 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_ascii_uppercase(), c.as_str().to_string())},
     }
 }
 
@@ -24,7 +22,12 @@ 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![]
+    let mut itr = words.iter();
+    let mut res = vec![];
+    while let Some(x) = itr.next() {
+        res.push(capitalize_first(x));
+    };
+    res
 }
 
 // Step 3.
@@ -32,7 +35,12 @@ 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()
+    let mut itr = words.iter();
+    let mut res = vec![];
+    while let Some(x) = itr.next() {
+        res.push(capitalize_first(x));
+    };
+    res.into_iter().collect()
 }
 
 #[cfg(test)]

exercises/iterators/iterators3.rs

@@ -9,8 +9,6 @@
 // Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
     NotDivisible(NotDivisibleError),
@@ -26,23 +24,32 @@ 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 {
+        return Err(DivisionError::DivideByZero);
+    }
+    let res = a % b;
+    if res != 0 {
+        return Err(DivisionError::NotDivisible(NotDivisibleError{ dividend: a, divisor: b}));
+    }
+    Ok(a/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));
+    division_results.collect()
 }
 
 // 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));
+    division_results.collect()
 }
 
 #[cfg(test)]

exercises/iterators/iterators4.rs

@@ -3,8 +3,6 @@
 // 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
     // Do not use:
@@ -15,6 +13,7 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    (1..num+1).fold(1, |acc, x| acc * x)
 }
 
 #[cfg(test)]

exercises/iterators/iterators5.rs

@@ -11,8 +11,6 @@
 // Execute `rustlings hint iterators5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Clone, Copy, PartialEq, Eq)]
@@ -35,7 +33,13 @@ 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!();
+    map.values().fold(0, |acc, x| {
+        if x == &value {
+            acc + 1
+        } else {
+            acc
+        }
+    })
 }
 
 fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -54,7 +58,9 @@ 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.iter().fold(0, |acc, x| {
+        acc + count_iterator(x, value)
+    })
 }
 
 #[cfg(test)]

exercises/lifetimes/lifetimes1.rs

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

exercises/lifetimes/lifetimes2.rs

@@ -6,8 +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() {
         x
@@ -19,8 +17,9 @@ fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
 fn main() {
     let string1 = String::from("long string is long");
     let result;
+    let string2;
     {
-        let string2 = String::from("xyz");
+        string2 = String::from("xyz");
         result = longest(string1.as_str(), string2.as_str());
     }
     println!("The longest string is '{}'", result);

exercises/lifetimes/lifetimes3.rs

@@ -5,11 +5,9 @@
 // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
+struct Book<'a> {
-
+    author: &'a str,
-struct Book {
+    title: &'a str,
-    author: &str,
-    title: &str,
 }
 
 fn main() {

exercises/modules/modules1.rs

@@ -3,15 +3,13 @@
 // 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!
     fn get_secret_recipe() -> String {
         String::from("Ginger")
     }
 
-    fn make_sausage() {
+    pub fn make_sausage() {
         get_secret_recipe();
         println!("sausage!");
     }

exercises/modules/modules2.rs

@@ -7,12 +7,10 @@
 // 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

@@ -8,10 +8,9 @@
 // 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 as SystemTime;
+use std::time::UNIX_EPOCH as UNIX_EPOCH;
 
 fn main() {
     match SystemTime::now().duration_since(UNIX_EPOCH) {

exercises/move_semantics/move_semantics1.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
     let vec0 = vec![22, 44, 66];
@@ -15,7 +13,7 @@ fn main() {
 }
 
 fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let vec = vec;
+    let mut vec = vec;
 
     vec.push(88);
 

exercises/move_semantics/move_semantics2.rs

@@ -5,13 +5,11 @@
 // Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
     let vec0 = vec![22, 44, 66];
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(vec0.clone());
 
     assert_eq!(vec0, vec![22, 44, 66]);
     assert_eq!(vec1, vec![22, 44, 66, 88]);

exercises/move_semantics/move_semantics3.rs

@@ -6,8 +6,6 @@
 // Execute `rustlings hint move_semantics3` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
     let vec0 = vec![22, 44, 66];
@@ -17,7 +15,7 @@ fn main() {
     assert_eq!(vec1, vec![22, 44, 66, 88]);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
     vec.push(88);
 
     vec

exercises/move_semantics/move_semantics4.rs

@@ -7,13 +7,9 @@
 // Execute `rustlings hint move_semantics4` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
-    let vec0 = vec![22, 44, 66];
+    let mut vec1 = fill_vec();
-
-    let mut vec1 = fill_vec(vec0);
 
     assert_eq!(vec1, vec![22, 44, 66, 88]);
 }
@@ -21,7 +17,7 @@ fn main() {
 // `fill_vec()` no longer takes `vec: Vec<i32>` as argument - don't change this!
 fn fill_vec() -> Vec<i32> {
     // Instead, let's create and fill the Vec in here - how do you do that?
-    let mut vec = vec;
+    let mut vec = vec![22, 44, 66];
 
     vec.push(88);
 

exercises/move_semantics/move_semantics5.rs

@@ -6,14 +6,12 @@
 // Execute `rustlings hint move_semantics5` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 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

@@ -5,24 +5,22 @@
 // Execute `rustlings hint move_semantics6` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 fn main() {
     let data = "Rust is great!".to_string();
 
-    get_char(data);
+    get_char(&data);
 
-    string_uppercase(&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) {
+fn string_uppercase(mut data: String) {
-    data = &data.to_uppercase();
+    data = data.to_uppercase();
 
     println!("{}", data);
 }

exercises/options/options1.rs

@@ -3,8 +3,6 @@
 // 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 :(
@@ -13,7 +11,12 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // value of 0 The Option output should gracefully handle cases where
     // time_of_day > 23.
     // TODO: Complete the function body - remember to return an Option!
-    ???
+    if (time_of_day < 22) {
+        return Some(5);
+    } else if (time_of_day >= 22 && time_of_day < 25)  {
+        return Some(0);
+    }
+    None
 }
 
 #[cfg(test)]
@@ -34,6 +37,6 @@ mod tests {
         // TODO: Fix this test. How do you get at the value contained in the
         // Option?
         let icecreams = maybe_icecream(12);
-        assert_eq!(icecreams, 5);
+        assert_eq!(icecreams, Some(5));
     }
 }

exercises/options/options2.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
@@ -13,7 +11,7 @@ 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);
         }
     }
@@ -32,7 +30,7 @@ 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(Some(integer)) = optional_integers.pop() {
             assert_eq!(integer, cursor);
             cursor -= 1;
         }

exercises/options/options3.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct Point {
     x: i32,
     y: i32,
@@ -14,8 +12,8 @@ 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); },
         _ => panic!("no match!"),
-    }
+    };
     y; // Fix without deleting this line.
 }

exercises/primitive_types/primitive_types1.rs

@@ -3,8 +3,6 @@
 // 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`)
 
@@ -13,7 +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;
     if is_evening {
         println!("Good evening!");
     }

exercises/primitive_types/primitive_types2.rs

@@ -3,8 +3,6 @@
 // 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`)
 
@@ -19,7 +17,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = 'D'; // 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

@@ -5,10 +5,8 @@
 // Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 fn main() {
-    let a = ???
+    let a = [0;101];
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");

exercises/primitive_types/primitive_types4.rs

@@ -5,13 +5,11 @@
 // 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..a.len()-1];
 
     assert_eq!([2, 3, 4], nice_slice)
 }

exercises/primitive_types/primitive_types5.rs

@@ -5,11 +5,9 @@
 // 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

@@ -6,13 +6,11 @@
 // 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

@@ -13,10 +13,10 @@
 //
 // No hints this time ;)
 
-// I AM NOT DONE
-
 // Put your function here!
-// fn calculate_price_of_apples {
+fn calculate_price_of_apples(x: u32) -> u32 {
+    if x > 40 { x } else { x * 2 }
+}
 
 // Don't modify this function!
 #[test]

exercises/quiz2.rs

@@ -20,8 +20,6 @@
 //
 // No hints this time!
 
-// I AM NOT DONE
-
 pub enum Command {
     Uppercase,
     Trim,
@@ -32,11 +30,22 @@ mod my_module {
     use super::Command;
 
     // TODO: Complete the function signature!
-    pub fn transformer(input: ???) -> ??? {
+    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
         // TODO: Complete the output declaration!
-        let mut output: ??? = vec![];
+        let mut output: Vec<String> = vec![];
         for (string, command) in input.iter() {
-            // TODO: Complete the function body. You can do it!
+            match command {
+                Command::Uppercase => {
+                    output.push(string.to_ascii_uppercase());
+                },
+                Command::Trim => {
+                    output.push(string.trim().to_string());
+                },
+                Command::Append(x) => {
+                    let barRepeated = "bar".repeat(*x);
+                    output.push(format!("{}{}", string, barRepeated));
+                }
+            };
         }
         output
     }
@@ -45,7 +54,7 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we need to import to have `transformer` in scope?
-    use ???;
+    use crate::my_module::transformer;
     use super::Command;
 
     #[test]

exercises/quiz3.rs

@@ -16,16 +16,18 @@
 //
 // Execute `rustlings hint quiz3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+pub struct ReportCard<T> {
-
+    pub grade: T,
-pub struct ReportCard {
-    pub grade: f32,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+trait ReportCardMethods {
-    pub fn print(&self) -> String {
+    fn print(&self) -> String;
+}
+
+impl<T: std::fmt::Display> ReportCardMethods for ReportCard<T> {
+    fn print(&self) -> String {
         format!("{} ({}) - achieved a grade of {}",
             &self.student_name, &self.student_age, &self.grade)
     }
@@ -52,7 +54,7 @@ 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/smart_pointers/arc1.rs

@@ -21,19 +21,17 @@
 //
 // 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/smart_pointers/box1.rs

@@ -18,11 +18,9 @@
 //
 // 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,
 }
 
@@ -35,11 +33,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    todo!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    todo!()
+    List::Cons(4, Box::new(List::Nil))
 }
 
 #[cfg(test)]

exercises/smart_pointers/cow1.rs

@@ -48,7 +48,8 @@ mod tests {
         let slice = [0, 1, 2];
         let mut input = Cow::from(&slice[..]);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Err("Unexpected error"),
+            _ => Ok(())
         }
     }
 
@@ -60,10 +61,12 @@ mod tests {
         let slice = vec![0, 1, 2];
         let mut input = Cow::from(slice);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Ok(()),
+            _ => Err("Expected owned value"),
         }
     }
 
+
     #[test]
     fn owned_mutation() -> Result<(), &'static str> {
         // Of course this is also the case if a mutation does occur. In this
@@ -72,7 +75,8 @@ mod tests {
         let slice = vec![-1, 0, 1];
         let mut input = Cow::from(slice);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Ok(()),
+            _ => Err("Expected owned value"),
         }
     }
 }

exercises/smart_pointers/rc1.rs

@@ -10,8 +10,6 @@
 //
 // Execute `rustlings hint rc1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::rc::Rc;
 
 #[derive(Debug)]
@@ -61,17 +59,17 @@ 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();
 
@@ -92,13 +90,13 @@ 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(venus);
     println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
 
-    // TODO
+    drop(mercury);
     println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
 
     assert_eq!(Rc::strong_count(&sun), 1);

exercises/strings/strings1.rs

@@ -5,13 +5,11 @@
 // Execute `rustlings hint strings1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     let answer = current_favorite_color();
-    println!("My current favorite color is {}", answer);
+    println!("My current favorite color is {}", answer.to_string());
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".to_string()
 }

exercises/strings/strings2.rs

@@ -5,11 +5,9 @@
 // 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) {
         println!("That is a color word I know!");
     } else {
         println!("That is not a color word I know.");

exercises/strings/strings3.rs

@@ -3,21 +3,24 @@
 // 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!
-    ???
+    let trimmed = input.trim();
+    return trimmed.to_string();
 }
 
 fn compose_me(input: &str) -> String {
     // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+    let mut inputStr: String = input.to_owned();
+    let worldStr = " world!";
+    inputStr.push_str(&worldStr);
+    return inputStr;
 }
 
 fn replace_me(input: &str) -> String {
     // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    let replaced = input.replace("cars", "balloons");
+    replaced.to_string()
 }
 
 #[cfg(test)]

exercises/strings/strings4.rs

@@ -7,8 +7,6 @@
 //
 // No hints this time!
 
-// I AM NOT DONE
-
 fn string_slice(arg: &str) {
     println!("{}", arg);
 }
@@ -17,14 +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

@@ -5,13 +5,13 @@
 // Execute `rustlings hint structs1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct ColorClassicStruct {
-    // TODO: Something goes here
+    red: u8,
+    green: u8,
+    blue: u8
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct(u8, u8, u8);
 
 #[derive(Debug)]
 struct UnitLikeStruct;
@@ -23,7 +23,11 @@ mod tests {
     #[test]
     fn classic_c_structs() {
         // TODO: Instantiate a classic c struct!
-        // let green =
+        let green = ColorClassicStruct{
+            red: 0,
+            green: 255,
+            blue: 0
+        };
 
         assert_eq!(green.red, 0);
         assert_eq!(green.green, 255);
@@ -33,7 +37,7 @@ mod tests {
     #[test]
     fn tuple_structs() {
         // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = ColorTupleStruct(0, 255, 0);
 
         assert_eq!(green.0, 0);
         assert_eq!(green.1, 255);
@@ -43,7 +47,7 @@ mod tests {
     #[test]
     fn unit_structs() {
         // TODO: Instantiate a unit-like struct!
-        // let unit_like_struct =
+        let unit_like_struct = UnitLikeStruct;
         let message = format!("{:?}s are fun!", unit_like_struct);
 
         assert_eq!(message, "UnitLikeStructs are fun!");

exercises/structs/structs2.rs

@@ -5,8 +5,6 @@
 // Execute `rustlings hint structs2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Order {
     name: String,
@@ -38,7 +36,9 @@ 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 mut your_order = create_order_template();
+        your_order.name = "Hacker in Rust".into();
+        your_order.count = 1;
         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

@@ -7,8 +7,6 @@
 // Execute `rustlings hint structs3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Package {
     sender_country: String,
@@ -31,12 +29,12 @@ 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: u32) -> ??? {
+    fn get_fees(&self, cents_per_gram: u32) -> u32 {
-        // Something goes here...
+        self.weight_in_grams * cents_per_gram
     }
 }
 

exercises/tests/tests1.rs

@@ -10,12 +10,10 @@
 // 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!(true);
     }
 }

exercises/tests/tests2.rs

@@ -6,12 +6,10 @@
 // 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!(true, true);
     }
 }

exercises/tests/tests3.rs

@@ -7,8 +7,6 @@
 // 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
 }
@@ -19,11 +17,11 @@ mod tests {
 
     #[test]
     fn is_true_when_even() {
-        assert!();
+        assert!(is_even(2));
     }
 
     #[test]
     fn is_false_when_odd() {
-        assert!();
+        assert!(is_even(3) == false);
     }
 }

exercises/tests/tests4.rs

@@ -5,8 +5,6 @@
 // Execute `rustlings hint tests4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct Rectangle {
     width: i32,
     height: i32
@@ -30,17 +28,19 @@ mod tests {
     fn correct_width_and_height() {
         // This test should check if the rectangle is the size that we pass into its constructor
         let rect = Rectangle::new(10, 20);
-        assert_eq!(???, 10); // check width
+        assert_eq!(rect.width, 10); // check width
-        assert_eq!(???, 20); // check height
+        assert_eq!(rect.height, 20); // check height
     }
 
     #[test]
+    #[should_panic]
     fn negative_width() {
         // This test should check if program panics when we try to create rectangle with negative width
         let _rect = Rectangle::new(-10, 10);
     }
 
     #[test]
+    #[should_panic]
     fn negative_height() {
         // This test should check if program panics when we try to create rectangle with negative height
         let _rect = Rectangle::new(10, -10);

exercises/traits/traits1.rs

@@ -7,14 +7,15 @@
 // Execute `rustlings hint traits1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
     // TODO: Implement `AppendBar` for type `String`.
+    fn append_bar(self) -> Self {
+        format!("{}{}", self, "Bar")
+    }
 }
 
 fn main() {

exercises/traits/traits2.rs

@@ -8,13 +8,17 @@
 //
 // Execute `rustlings hint traits2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 // TODO: Implement trait `AppendBar` for a vector of strings.
+impl AppendBar for Vec<String> {
+    fn append_bar(mut self) -> Self {
+        self.push("Bar".to_string());
+        self
+    }
+}
 
 #[cfg(test)]
 mod tests {

exercises/traits/traits3.rs

@@ -8,10 +8,10 @@
 // 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".to_string()
+    }
 }
 
 struct SomeSoftware {
@@ -25,6 +25,8 @@ struct OtherSoftware {
 impl Licensed for SomeSoftware {} // Don't edit this line
 impl Licensed for OtherSoftware {} // Don't edit this line
 
+
+
 #[cfg(test)]
 mod tests {
     use super::*;

exercises/traits/traits4.rs

@@ -7,8 +7,6 @@
 // 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 {
         "some information".to_string()
@@ -23,7 +21,7 @@ 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

@@ -7,8 +7,6 @@
 // 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 {
         true
@@ -30,7 +28,7 @@ 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

@@ -5,9 +5,7 @@
 // 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

@@ -3,10 +3,8 @@
 // Execute `rustlings hint variables2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
-    let x;
+    let x = 10;
     if x == 10 {
         println!("x is ten!");
     } else {

exercises/variables/variables3.rs

@@ -3,9 +3,7 @@
 // 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 = 10;
     println!("Number {}", x);
 }

exercises/variables/variables4.rs

@@ -3,10 +3,8 @@
 // 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

@@ -3,11 +3,9 @@
 // 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

@@ -3,9 +3,7 @@
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
+const NUMBER: i32 = 3;
-
-const NUMBER = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }

exercises/vecs/vecs1.rs

@@ -7,11 +7,9 @@
 //
 // Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
 
-// 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
+    let v = vec![10, 20, 30, 40]; // TODO: declare your vector here with the macro for vectors
 
     (a, v)
 }

exercises/vecs/vecs2.rs

@@ -7,13 +7,11 @@
 //
 // 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 element in v.iter_mut() {
         // TODO: Fill this up so that each element in the Vec `v` is
         // multiplied by 2.
-        ???
+        *element *= 2;
     }
 
     // At this point, `v` should be equal to [4, 8, 12, 16, 20].
@@ -24,7 +22,7 @@ fn vec_map(v: &Vec<i32>) -> Vec<i32> {
     v.iter().map(|element| {
         // TODO: Do the same thing as above - but instead of mutating the
         // Vec, you can just return the new number!
-        ???
+        element * 2
     }).collect()
 }