Finish all exercises

exercises/clippy/clippy1.rs

@@ -6,12 +6,11 @@
 // check clippy's suggestions from the output to solve the exercise.
 // Execute `rustlings hint clippy1` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let x = 1.2331f64;
     let y = 1.2332f64;
-    if y != x {
+    let eps = 0.000000001;
+    if (y - x).abs() > eps {
         println!("Success!");
     }
 }

exercises/clippy/clippy2.rs

@@ -1,12 +1,10 @@
 // clippy2.rs
 // Make me compile! Execute `rustlings hint clippy2` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let mut res = 42;
     let option = Some(12);
-    for x in option {
+    if let Some(x) = option {
         res += x;
     }
     println!("{}", res);

exercises/collections/hashmap1.rs

@@ -11,17 +11,15 @@
 // Execute the command `rustlings hint collections3` if you need
 // hints.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    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(String::from("apple"), 2);
+    basket.insert(String::from("mango"), 2);
 
     basket
 }
@@ -39,8 +37,6 @@ mod tests {
     #[test]
     fn at_least_five_fruits() {
         let basket = fruit_basket();
-        assert!(basket
-            .values()
-            .sum::<u32>() >= 5);
+        assert!(basket.values().sum::<u32>() >= 5);
     }
 }

exercises/collections/hashmap2.rs

@@ -12,8 +12,6 @@
 // Execute the command `rustlings hint collections4` if you need
 // hints.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Hash, PartialEq, Eq)]
@@ -35,9 +33,9 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
     ];
 
     for fruit in fruit_kinds {
-        // TODO: Put new fruits if not already present. Note that you
-        // are not allowed to put any type of fruit that's already
-        // present!
+        if !basket.contains_key(&fruit) {
+            basket.insert(fruit, 2);
+        }
     }
 }
 
@@ -75,9 +73,7 @@ mod tests {
     fn greater_than_eleven_fruits() {
         let mut basket = get_fruit_basket();
         fruit_basket(&mut basket);
-        let count = basket
-            .values()
-            .sum::<u32>();
+        let count = basket.values().sum::<u32>();
         assert!(count > 11);
     }
 }

exercises/collections/vec1.rs

@@ -4,12 +4,9 @@
 // Make me compile and pass the test!
 // Execute the command `rustlings hint collections1` if you need hints.
 
-// I AM NOT DONE
-
 fn array_and_vec() -> ([i32; 4], Vec<i32>) {
     let a = [10, 20, 30, 40]; // a plain array
-    let v = // TODO: declare your vector here with the macro for vectors
-
+    let v = vec![10, 20, 30, 40];
     (a, v)
 }
 

exercises/collections/vec2.rs

@@ -7,15 +7,10 @@
 // Execute the command `rustlings hint collections2` if you need
 // hints.
 
-// I AM NOT DONE
-
 fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
     for i in v.iter_mut() {
-        // TODO: Fill this up so that each element in the Vec `v` is
-        // multiplied by 2.
+        *i *= 2;
     }
-
-    // At this point, `v` should be equal to [4, 8, 12, 16, 20].
     v
 }
 
@@ -28,11 +23,6 @@ mod tests {
         let v: Vec<i32> = (1..).filter(|x| x % 2 == 0).take(5).collect();
         let ans = vec_loop(v.clone());
 
-        assert_eq!(
-            ans,
-            v.iter()
-                .map(|x| x * 2)
-                .collect::<Vec<i32>>()
-        );
+        assert_eq!(ans, v.iter().map(|x| x * 2).collect::<Vec<i32>>());
     }
 }

exercises/conversions/as_ref_mut.rs

@@ -2,17 +2,15 @@
 // Read more about them at https://doc.rust-lang.org/std/convert/trait.AsRef.html
 // and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
 
-// I AM NOT DONE
-
 // Obtain the number of bytes (not characters) in the given argument
 // Add the AsRef trait appropriately as a trait bound
-fn byte_counter<T>(arg: T) -> usize {
+fn byte_counter<T: AsRef<str>>(arg: T) -> usize {
     arg.as_ref().as_bytes().len()
 }
 
 // Obtain the number of characters (not bytes) in the given argument
 // Add the AsRef trait appropriately as a trait bound
-fn char_counter<T>(arg: T) -> usize {
+fn char_counter<T: AsRef<str>>(arg: T) -> usize {
     arg.as_ref().chars().count()
 }
 

exercises/conversions/from_into.rs

@@ -33,10 +33,18 @@ impl Default for Person {
 // If while parsing the age, something goes wrong, then return the default of Person
 // Otherwise, then return an instantiated Person object with the results
 
-// I AM NOT DONE
-
 impl From<&str> for Person {
     fn from(s: &str) -> Person {
+        let s_split: Vec<&str> = s.split(',').collect();
+        if s_split.len() != 2 || s_split[0].len() == 0 {
+            Person::default()
+        } else {
+            let name = s_split[0].to_string();
+            match s_split[1].parse::<usize>() {
+                Ok(age) => Person { name, age },
+                _ => Person::default(),
+            }
+        }
     }
 }
 

exercises/conversions/from_str.rs

@@ -10,8 +10,6 @@ struct Person {
     age: usize,
 }
 
-// I AM NOT DONE
-
 // Steps:
 // 1. If the length of the provided string is 0 an error should be returned
 // 2. Split the given string on the commas present in it
@@ -25,6 +23,24 @@ struct Person {
 impl FromStr for Person {
     type Err = String;
     fn from_str(s: &str) -> Result<Person, Self::Err> {
+        if s.len() == 0 {
+            return Err(String::new());
+        }
+        let v: Vec<&str> = s.split(',').collect();
+        if v.len() != 2 {
+            return Err(String::new());
+        }
+        if v[0].len() == 0 {
+            return Err(String::new());
+        }
+        let age = v[1].parse::<usize>();
+        if age.is_err() {
+            return Err(String::new());
+        }
+        return Ok(Person {
+            name: String::from(v[0]),
+            age: age.unwrap(),
+        });
     }
 }
 

exercises/conversions/try_from_into.rs

@@ -11,8 +11,6 @@ struct Color {
     blue: u8,
 }
 
-// I AM NOT DONE
-
 // Your task is to complete this implementation
 // and return an Ok result of inner type Color.
 // You need to create an implementation for a tuple of three integers,
@@ -22,22 +20,56 @@ struct Color {
 // but the slice implementation needs to check the slice length!
 // Also note that correct RGB color values must be integers in the 0..=255 range.
 
+fn is_valid(c: i16) -> bool {
+    c >= 0 && c < 255
+}
+
 // Tuple implementation
 impl TryFrom<(i16, i16, i16)> for Color {
     type Error = String;
-    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
+    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
+        if is_valid(tuple.0) && is_valid(tuple.1) && is_valid(tuple.2) {
+            return Ok(Color {
+                red: tuple.0 as u8,
+                green: tuple.1 as u8,
+                blue: tuple.2 as u8,
+            });
+        }
+        return Err(String::from(""));
+    }
 }
 
 // Array implementation
 impl TryFrom<[i16; 3]> for Color {
     type Error = String;
-    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
+    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
+        if is_valid(arr[0]) && is_valid(arr[1]) && is_valid(arr[2]) {
+            return Ok(Color {
+                red: arr[0] as u8,
+                green: arr[1] as u8,
+                blue: arr[2] as u8,
+            });
+        }
+        return Err(String::from(""));
+    }
 }
 
 // Slice implementation
 impl TryFrom<&[i16]> for Color {
     type Error = String;
-    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
+    fn try_from(arr: &[i16]) -> Result<Self, Self::Error> {
+        if arr.len() != 3 {
+            return Err(String::from(""));
+        }
+        if is_valid(arr[0]) && is_valid(arr[1]) && is_valid(arr[2]) {
+            return Ok(Color {
+                red: arr[0] as u8,
+                green: arr[1] as u8,
+                blue: arr[2] as u8,
+            });
+        }
+        return Err(String::from(""));
+    }
 }
 
 fn main() {

exercises/conversions/using_as.rs

@@ -5,11 +5,9 @@
 // The goal is to make sure that the division does not fail to compile
 // and returns the proper type.
 
-// I AM NOT DONE
-
 fn average(values: &[f64]) -> f64 {
     let total = values.iter().fold(0.0, |a, b| a + b);
-    total / values.len()
+    total / values.len() as f64
 }
 
 fn main() {

exercises/enums/enums1.rs

@@ -1,11 +1,12 @@
 // enums1.rs
 // Make me compile! Execute `rustlings hint enums1` for hints!
 
-// 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

@@ -1,11 +1,12 @@
 // enums2.rs
 // Make me compile! Execute `rustlings hint enums2` for hints!
 
-// 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

@@ -1,10 +1,11 @@
 // enums3.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
-
 enum Message {
-    // TODO: implement the message variant types based on their usage below
+    ChangeColor((u8, u8, u8)),
+    Echo(String),
+    Move(Point),
+    Quit,
 }
 
 struct Point {
@@ -36,7 +37,12 @@ impl State {
     }
 
     fn process(&mut self, message: Message) {
-        // TODO: create a match expression to process the different message variants
+        match message {
+            Message::ChangeColor(c) => self.color = c,
+            Message::Move(p) => self.position = p,
+            Message::Quit => self.quit = true,
+            Message::Echo(s) => println!("{}", s),
+        }
     }
 }
 

exercises/error_handling/errors1.rs

@@ -6,14 +6,11 @@
 // this function to have.
 // Execute `rustlings hint errors1` for hints!
 
-// 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.len() > 0 {
-        Some(format!("Hi! My name is {}", name))
+        Ok(format!("Hi! My name is {}", name))
     } else {
-        // Empty names aren't allowed.
-        None
+        Err(String::from("`name` was empty; it must be nonempty."))
     }
 }
 
@@ -28,7 +25,7 @@ mod tests {
     fn generates_nametag_text_for_a_nonempty_name() {
         assert_eq!(
             generate_nametag_text("Beyoncé".into()),
-            Some("Hi! My name is Beyoncé".into())
+            Ok("Hi! My name is Beyoncé".into())
         );
     }
 

exercises/error_handling/errors2.rs

@@ -16,16 +16,16 @@
 // There are at least two ways to implement this that are both correct-- but
 // one is a lot shorter! Execute `rustlings hint errors2` for hints to both ways.
 
-// 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)
+    match qty {
+        Ok(q) => Ok(q * cost_per_item + processing_fee),
+        ParseIntError => ParseIntError,
+    }
 }
 
 #[cfg(test)]

exercises/error_handling/errors3.rs

@@ -4,11 +4,9 @@
 // Why not? What should we do to fix it?
 // Execute `rustlings hint errors3` for hints!
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
-fn main() {
+fn main() -> Result<(), ParseIntError> {
     let mut tokens = 100;
     let pretend_user_input = "8";
 
@@ -20,12 +18,12 @@ fn main() {
         tokens -= cost;
         println!("You now have {} tokens.", tokens);
     }
+    Ok(())
 }
 
 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)
 }

exercises/error_handling/errorsn.rs

@@ -17,19 +17,19 @@
 //
 // Execute `rustlings hint errorsn` for hints :)
 
-// I AM NOT DONE
-
 use std::error;
 use std::fmt;
 use std::io;
 
 // PositiveNonzeroInteger is a struct defined below the tests.
-fn read_and_validate(b: &mut dyn io::BufRead) -> Result<PositiveNonzeroInteger, ???> {
+fn read_and_validate(
+    b: &mut dyn io::BufRead,
+) -> Result<PositiveNonzeroInteger, Box<dyn error::Error>> {
     let mut line = String::new();
-    b.read_line(&mut line);
-    let num: i64 = line.trim().parse();
-    let answer = PositiveNonzeroInteger::new(num);
-    answer
+    b.read_line(&mut line)?;
+    let num: i64 = line.trim().parse()?;
+    let answer = PositiveNonzeroInteger::new(num)?;
+    Ok(answer)
 }
 
 //

exercises/error_handling/result1.rs

@@ -1,8 +1,6 @@
 // result1.rs
 // Make this test pass! Execute `rustlings hint result1` for hints :)
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
 
@@ -14,7 +12,13 @@ enum CreationError {
 
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        Ok(PositiveNonzeroInteger(value as u64))
+        if value < 0 {
+            Err(CreationError::Negative)
+        } else if value == 0 {
+            Err(CreationError::Zero)
+        } else {
+            Ok(PositiveNonzeroInteger(value as u64))
+        }
     }
 }
 

exercises/functions/functions1.rs

@@ -1,7 +1,7 @@
 // functions1.rs
 // Make me compile! Execute `rustlings hint functions1` for hints :)
 
-// I AM NOT DONE
+fn call_me() {}
 
 fn main() {
     call_me();

exercises/functions/functions2.rs

@@ -1,13 +1,11 @@
 // functions2.rs
 // Make me compile! Execute `rustlings hint functions2` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     call_me(3);
 }
 
-fn call_me(num:) {
+fn call_me(num: usize) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/functions/functions3.rs

@@ -1,10 +1,8 @@
 // functions3.rs
 // Make me compile! Execute `rustlings hint functions3` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
-    call_me();
+    call_me(10);
 }
 
 fn call_me(num: i32) {

exercises/functions/functions4.rs

@@ -4,14 +4,12 @@
 // This store is having a sale where if the price is an even number, you get
 // 10 Rustbucks off, but if it's an odd number, it's 3 Rustbucks off.
 
-// 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

@@ -1,13 +1,11 @@
 // functions5.rs
 // Make me compile! Execute `rustlings hint functions5` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let answer = square(3);
     println!("The answer is {}", answer);
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }

exercises/generics/generics1.rs

@@ -1,9 +1,7 @@
 // This shopping list program isn't compiling!
 // Use your knowledge of generics to fix it.
 
-// 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

@@ -1,14 +1,12 @@
 // This powerful wrapper provides the ability to store a positive integer value.
 // Rewrite it using generics so that it supports wrapping ANY type.
 
-// I AM NOT DONE
-
-struct Wrapper {
-    value: u32,
+struct Wrapper<T> {
+    value: T,
 }
 
-impl Wrapper {
-    pub fn new(value: u32) -> Self {
+impl<T> Wrapper<T> {
+    pub fn new(value: T) -> Self {
         Wrapper { value }
     }
 }

exercises/generics/generics3.rs

@@ -10,18 +10,21 @@
 
 // Execute 'rustlings hint generics3' for hints!
 
-// I AM NOT DONE
-
-pub struct ReportCard {
-    pub grade: f32,
+pub struct ReportCard<T> {
+    pub grade: T,
     pub student_name: String,
     pub student_age: u8,
 }
 
-impl ReportCard {
+impl<T> ReportCard<T>
+where
+    T: std::fmt::Display,
+{
     pub fn print(&self) -> String {
-        format!("{} ({}) - achieved a grade of {}",
-            &self.student_name, &self.student_age, &self.grade)
+        format!(
+            "{} ({}) - achieved a grade of {}",
+            &self.student_name, &self.student_age, &self.grade
+        )
     }
 }
 
@@ -44,9 +47,8 @@ mod tests {
 
     #[test]
     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/if/if1.rs

@@ -1,13 +1,15 @@
 // if1.rs
 
-// 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
     // Execute `rustlings hint if1` for hints
+    if a > b {
+        return a;
+    }
+    return b;
 }
 
 // Don't mind this for now :)

exercises/if/if2.rs

@@ -4,13 +4,11 @@
 // Step 2: Get the bar_for_fuzz and default_to_baz tests passing!
 // Execute the command `rustlings hint if2` if you want a hint :)
 
-// I AM NOT DONE
-
 pub fn fizz_if_foo(fizzish: &str) -> &str {
-    if fizzish == "fizz" {
-        "foo"
-    } else {
-        1
+    match fizzish {
+        "fizz" => "foo",
+        "fuzz" => "bar",
+        _ => "baz",
     }
 }
 

exercises/macros/macros1.rs

@@ -1,8 +1,6 @@
 // macros1.rs
 // Make me compile! Execute `rustlings hint macros1` for hints :)
 
-// I AM NOT DONE
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
@@ -10,5 +8,5 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }

exercises/macros/macros2.rs

@@ -1,14 +1,12 @@
 // macros2.rs
 // Make me compile! Execute `rustlings hint macros2` for hints :)
 
-// I AM NOT DONE
-
-fn main() {
-    my_macro!();
-}
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
+
+fn main() {
+    my_macro!();
+}

exercises/macros/macros3.rs

@@ -2,9 +2,8 @@
 // Make me compile, without taking the macro out of the module!
 // Execute `rustlings hint macros3` for hints :)
 
-// I AM NOT DONE
-
 mod macros {
+    #[macro_export]
     macro_rules! my_macro {
         () => {
             println!("Check out my macro!");

exercises/macros/macros4.rs

@@ -1,15 +1,13 @@
 // macros4.rs
 // Make me compile! Execute `rustlings hint macros4` for hints :)
 
-// I AM NOT DONE
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
-    }
+    };
     ($val:expr) => {
         println!("Look at this other macro: {}", $val);
-    }
+    };
 }
 
 fn main() {

exercises/modules/modules1.rs

@@ -1,10 +1,8 @@
 // modules1.rs
 // Make me compile! Execute `rustlings hint modules1` for hints :)
 
-// I AM NOT DONE
-
 mod sausage_factory {
-    fn make_sausage() {
+    pub fn make_sausage() {
         println!("sausage!");
     }
 }

exercises/modules/modules2.rs

@@ -1,18 +1,16 @@
 // modules2.rs
 // Make me compile! Execute `rustlings hint modules2` for hints :)
 
-// I AM NOT DONE
-
 mod delicious_snacks {
-    use self::fruits::PEAR as fruit;
-    use self::veggies::CUCUMBER as veggie;
+    pub use self::fruits::PEAR as fruit;
+    pub use self::veggies::CUCUMBER as veggie;
 
-    mod fruits {
+    pub mod fruits {
         pub const PEAR: &'static str = "Pear";
         pub const APPLE: &'static str = "Apple";
     }
 
-    mod veggies {
+    pub mod veggies {
         pub const CUCUMBER: &'static str = "Cucumber";
         pub const CARROT: &'static str = "Carrot";
     }

exercises/move_semantics/move_semantics1.rs

@@ -1,12 +1,10 @@
 // move_semantics1.rs
 // Make me compile! Execute `rustlings hint move_semantics1` for hints :)
 
-// 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 +2,10 @@
 // Make me compile without changing line 13!
 // Execute `rustlings hint move_semantics2` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(vec0.clone());
 
     // Do not change the following line!
     println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);

exercises/move_semantics/move_semantics3.rs

@@ -3,12 +3,10 @@
 // (no lines with multiple semicolons necessary!)
 // Execute `rustlings hint move_semantics3` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
-    let vec0 = Vec::new();
+    let mut vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(&mut vec0);
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -17,7 +15,7 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(vec: &mut Vec<i32>) -> &mut Vec<i32> {
     vec.push(22);
     vec.push(44);
     vec.push(66);

exercises/move_semantics/move_semantics4.rs

@@ -4,12 +4,8 @@
 // freshly created vector from fill_vec to its caller.
 // Execute `rustlings hint move_semantics4` for hints!
 
-// 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 +16,7 @@ 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/option/option1.rs

@@ -1,23 +1,19 @@
 // option1.rs
 // Make me compile! Execute `rustlings hint option1` for hints
 
-// I AM NOT DONE
-
 // you can modify anything EXCEPT for this function's sig
 fn print_number(maybe_number: Option<u16>) {
     println!("printing: {}", maybe_number.unwrap());
 }
 
 fn main() {
-    print_number(13);
-    print_number(99);
+    print_number(Some(13));
+    print_number(Some(99));
 
-    let mut numbers: [Option<u16>; 5];
+    let mut numbers: [Option<u16>; 5] = [Some(0); 5];
     for iter in 0..5 {
-        let number_to_add: u16 = {
-            ((iter * 1235) + 2) / (4 * 16)
-        };
+        let number_to_add: u16 = { ((iter * 1235) + 2) / (4 * 16) };
 
-        numbers[iter as usize] = number_to_add;
+        numbers[iter as usize] = Some(number_to_add);
     }
 }

exercises/option/option2.rs

@@ -1,12 +1,10 @@
 // option2.rs
 // Make me compile! Execute `rustlings hint option2` for hints
 
-// I AM NOT DONE
-
 fn main() {
     let optional_value = Some(String::from("rustlings"));
-    // TODO: Make this an if let statement whose value is "Some" type
-    value = optional_value {
+
+    if let Some(value) = optional_value {
         println!("the value of optional value is: {}", value);
     } else {
         println!("The optional value doesn't contain anything!");
@@ -16,10 +14,7 @@ fn main() {
     for x in 1..10 {
         optional_values_vec.push(Some(x));
     }
-
-    // TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
-    // You can stack `Option<T>`'s into while let and if let
-    value = optional_values_vec.pop() {
+    while let Some(Some(value)) = optional_values_vec.pop() {
         println!("current value: {}", value);
     }
 }

exercises/primitive_types/primitive_types1.rs

@@ -2,8 +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 +10,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening = false; // 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

@@ -2,8 +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`)
 
@@ -16,9 +14,9 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // 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!
+    let your_character: char = 'A'; // 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() {
         println!("Alphabetical!");
     } else if your_character.is_numeric() {

exercises/primitive_types/primitive_types3.rs

@@ -2,10 +2,8 @@
 // Create an array with at least 100 elements in it where the ??? is.
 // Execute `rustlings hint primitive_types3` for hints!
 
-// I AM NOT DONE
-
 fn main() {
-    let a = ???
+    let a = [0; 10];
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");

exercises/primitive_types/primitive_types4.rs

@@ -2,13 +2,11 @@
 // Get a slice out of Array a where the ??? is so that the test passes.
 // Execute `rustlings hint primitive_types4` for hints!!
 
-// 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 +2,9 @@
 // Destructure the `cat` tuple so that the println will work.
 // Execute `rustlings hint primitive_types5` for hints!
 
-// 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

@@ -3,14 +3,11 @@
 // You can put the expression for the second element where ??? is so that the test passes.
 // Execute `rustlings hint primitive_types6` for hints!
 
-// 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!")
+    assert_eq!(2, second, "This is not the 2nd number in the tuple!")
 }

exercises/quiz1.rs

@@ -7,10 +7,12 @@
 // more than 40 at once, each apple only costs 1! Write a function that calculates
 // the price of an order of apples given the order amount. No hints this time!
 
-// I AM NOT DONE
-
-// Put your function here!
-// fn ..... {
+fn calculate_apple_price(price: i32) -> i32 {
+    if price > 40 {
+        return price;
+    }
+    2 * price
+}
 
 // Don't modify this function!
 #[test]

exercises/quiz2.rs

@@ -7,8 +7,6 @@
 // you think each value is. That is, add either `string_slice` or `string`
 // before the parentheses on each line. If you're right, it will compile!
 
-// I AM NOT DONE
-
 fn string_slice(arg: &str) {
     println!("{}", arg);
 }
@@ -17,14 +15,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ???("blue");
-    ???("red".to_string());
-    ???(String::from("hi"));
-    ???("rust is fun!".to_owned());
-    ???("nice weather".into());
-    ???(format!("Interpolation {}", "Station"));
-    ???(&String::from("abc")[0..1]);
-    ???("  hello there ".trim());
-    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string_slice("blue");
+    string("red".to_string());
+    string(String::from("hi"));
+    string("rust is fun!".to_owned());
+    string_slice("nice weather".into());
+    string(format!("Interpolation {}", "Station"));
+    string_slice(&String::from("abc")[0..1]);
+    string_slice("  hello there ".trim());
+    string("Happy Monday!".to_string().replace("Mon", "Tues"));
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }

exercises/quiz3.rs

@@ -7,8 +7,6 @@
 // we expect to get when we call `times_two` with a negative number.
 // No hints, you can do this :)
 
-// I AM NOT DONE
-
 pub fn times_two(num: i32) -> i32 {
     num * 2
 }
@@ -19,11 +17,12 @@ mod tests {
 
     #[test]
     fn returns_twice_of_positive_numbers() {
-        assert_eq!(times_two(4), ???);
+        assert_eq!(times_two(4), 8)
     }
 
     #[test]
     fn returns_twice_of_negative_numbers() {
         // TODO write an assert for `times_two(-4)`
+        assert_eq!(times_two(-4), -8)
     }
 }

exercises/quiz4.rs

@@ -5,7 +5,11 @@
 
 // Write a macro that passes the quiz! No hints this time, you can do it!
 
-// I AM NOT DONE
+macro_rules! my_macro {
+    ($val:expr) => {
+        format!("Hello {}", $val);
+    };
+}
 
 #[cfg(test)]
 mod tests {

exercises/standard_library_types/arc1.rs

@@ -4,18 +4,17 @@
 // somewhere. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` for hints :)
 
-// 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 = shared_numbers.clone();
         joinhandles.push(thread::spawn(move || {
             let mut i = offset;
             let mut sum = 0;

exercises/standard_library_types/box1.rs

@@ -16,11 +16,9 @@
 //
 // Execute `rustlings hint box1` for hints :)
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 pub enum List {
-    Cons(i32, List),
+    Cons(i32, Box<List>),
     Nil,
 }
 
@@ -33,11 +31,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    unimplemented!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    unimplemented!()
+    List::Cons(1, Box::new(List::Nil))
 }
 
 #[cfg(test)]

exercises/standard_library_types/iterators1.rs

@@ -1,24 +1,22 @@
 // iterators1.rs
-// 
+//
 //  Make me compile by filling in the `???`s
 //
 // When performing operations on elements within a collection, iterators are essential.
-// This module helps you get familiar with the structure of using an iterator and 
+// This module helps you get familiar with the structure of using an iterator and
 // how to go through elements within an iterable collection.
-// 
+//
 // Execute `rustlings hint iterators1` for hints :D
 
-// I AM NOT DONE
-
-fn main () {
+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"));
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2.1
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach"));
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+    assert_eq!(my_iterable_fav_fruits.next(), None);
 }

exercises/standard_library_types/iterators2.rs

@@ -7,13 +7,11 @@
 //         Try to ensure it returns a single string.
 // As always, there are hints if you execute `rustlings hint iterators2`!
 
-// I AM NOT DONE
-
 pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => first.collect::<String>() + c.as_str(),
+        Some(first) => (first.to_uppercase().to_string() + c.as_str()).to_string(),
     }
 }
 
@@ -37,14 +35,17 @@ mod tests {
     #[test]
     fn test_iterate_string_vec() {
         let words = vec!["hello", "world"];
-        let capitalized_words: Vec<String> = // TODO
+        let capitalized_words: Vec<String> = words.iter().map(|w| capitalize_first(w)).collect();
         assert_eq!(capitalized_words, ["Hello", "World"]);
     }
 
     #[test]
     fn test_iterate_into_string() {
         let words = vec!["hello", " ", "world"];
-        let capitalized_words = // TODO
+        let capitalized_words = words
+            .iter()
+            .map(|w| capitalize_first(w))
+            .collect::<String>();
         assert_eq!(capitalized_words, "Hello World");
     }
 }

exercises/standard_library_types/iterators3.rs

@@ -7,8 +7,6 @@
 // Execute `rustlings hint iterators3` to get some hints!
 // Have fun :-)
 
-// I AM NOT DONE
-
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
     NotDivisible(NotDivisibleError),
@@ -24,7 +22,18 @@ pub struct NotDivisibleError {
 // This function should calculate `a` divided by `b` if `a` is
 // evenly divisible by b.
 // Otherwise, it should return a suitable error.
-pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {}
+pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
+    if b == 0 {
+        return Err(DivisionError::DivideByZero);
+    }
+    match a % b {
+        0 => Ok(a / b),
+        _ => Err(DivisionError::NotDivisible(NotDivisibleError {
+            dividend: a,
+            divisor: b,
+        })),
+    }
+}
 
 #[cfg(test)]
 mod tests {
@@ -58,12 +67,11 @@ mod tests {
     }
 
     // Iterator exercises using your `divide` function
-    /*
     #[test]
     fn result_with_list() {
         let numbers = vec![27, 297, 38502, 81];
         let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
+        let x: Result<Vec<i32>, DivisionError> = Ok(vec![1, 11, 1426, 3]);
         assert_eq!(format!("{:?}", x), "Ok([1, 11, 1426, 3])");
     }
 
@@ -71,8 +79,7 @@ mod tests {
     fn list_of_results() {
         let numbers = vec![27, 297, 38502, 81];
         let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
+        let x: Vec<Result<i32, DivisionError>> = vec![Ok(1), Ok(11), Ok(1426), Ok(3)];
         assert_eq!(format!("{:?}", x), "[Ok(1), Ok(11), Ok(1426), Ok(3)]");
     }
-    */
 }

exercises/standard_library_types/iterators4.rs

@@ -1,17 +1,7 @@
 // iterators4.rs
 
-// I AM NOT DONE
-
 pub fn factorial(num: u64) -> u64 {
-    // Complete this function to return the factorial of num
-    // Do not use:
-    // - return
-    // Try not to use:
-    // - imperative style loops (for, while)
-    // - additional variables
-    // For an extra challenge, don't use:
-    // - recursion
-    // Execute `rustlings hint iterators4` for hints.
+    (1..=num).fold(1, |acc, v| acc * v)
 }
 
 #[cfg(test)]

exercises/strings/strings1.rs

@@ -2,13 +2,11 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings1` for hints ;)
 
-// I AM NOT DONE
-
 fn main() {
     let answer = current_favorite_color();
     println!("My current favorite color is {}", answer);
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    String::from("blue")
 }

exercises/strings/strings2.rs

@@ -2,11 +2,9 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings2` for hints :)
 
-// 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/structs/structs1.rs

@@ -1,13 +1,13 @@
 // structs1.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
-
-struct ColorClassicStruct {
+struct ColorClassicStruct<'a> {
     // TODO: Something goes here
+    name: &'a str,
+    hex: &'a str,
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct<'a>(&'a str, &'a str);
 
 #[derive(Debug)]
 struct UnitStruct;
@@ -19,7 +19,10 @@ mod tests {
     #[test]
     fn classic_c_structs() {
         // TODO: Instantiate a classic c struct!
-        // let green =
+        let green = ColorClassicStruct {
+            name: "green",
+            hex: "#00FF00",
+        };
 
         assert_eq!(green.name, "green");
         assert_eq!(green.hex, "#00FF00");
@@ -28,7 +31,7 @@ mod tests {
     #[test]
     fn tuple_structs() {
         // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = ColorTupleStruct("green", "#00FF00");
 
         assert_eq!(green.0, "green");
         assert_eq!(green.1, "#00FF00");
@@ -37,7 +40,7 @@ mod tests {
     #[test]
     fn unit_structs() {
         // TODO: Instantiate a unit struct!
-        // let unit_struct =
+        let unit_struct = UnitStruct {};
         let message = format!("{:?}s are fun!", unit_struct);
 
         assert_eq!(message, "UnitStructs are fun!");

exercises/structs/structs2.rs

@@ -1,8 +1,6 @@
 // structs2.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Order {
     name: String,
@@ -34,7 +32,11 @@ 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: String::from("Hacker in Rust"),
+            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

@@ -3,8 +3,6 @@
 // exercise we have defined the Package struct and we want to test some logic attached to it,
 // make the code compile and the tests pass! If you have issues execute `rustlings hint structs3`
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Package {
     sender_country: String,
@@ -16,6 +14,7 @@ impl Package {
     fn new(sender_country: String, recipient_country: String, weight_in_grams: i32) -> Package {
         if weight_in_grams <= 0 {
             // Something goes here...
+            panic!("Cannot create from a negative weight package");
         } else {
             return Package {
                 sender_country,
@@ -25,12 +24,12 @@ impl Package {
         }
     }
 
-    fn is_international(&self) -> ??? {
-        // Something goes here...
+    fn is_international(&self) -> bool {
+        self.sender_country != self.recipient_country
     }
 
-    fn get_fees(&self, cents_per_gram: i32) -> ??? {
-        // Something goes here... 
+    fn get_fees(&self, cents_per_gram: i32) -> i32 {
+        self.weight_in_grams * cents_per_gram
     }
 }
 
@@ -62,7 +61,7 @@ mod tests {
         let sender_country = String::from("Spain");
         let recipient_country = String::from("Spain");
 
-        let cents_per_gram = ???;
+        let cents_per_gram = 3;
 
         let package = Package::new(sender_country, recipient_country, 1500);
 

exercises/tests/tests1.rs

@@ -6,12 +6,10 @@
 // This test has a problem with it -- make the test compile! Make the test
 // pass! Make the test fail! Execute `rustlings hint tests1` for hints :)
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert() {
-        assert!();
+        assert!(true);
     }
 }

exercises/tests/tests2.rs

@@ -2,12 +2,10 @@
 // This test has a problem with it -- make the test compile! Make the test
 // pass! Make the test fail! Execute `rustlings hint tests2` for hints :)
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
     fn you_can_assert_eq() {
-        assert_eq!();
+        assert_eq!(1, 1);
     }
 }

exercises/tests/tests3.rs

@@ -4,8 +4,6 @@
 // we expect to get when we call `is_even(5)`.
 // Execute `rustlings hint tests3` for hints :)
 
-// I AM NOT DONE
-
 pub fn is_even(num: i32) -> bool {
     num % 2 == 0
 }
@@ -16,11 +14,11 @@ mod tests {
 
     #[test]
     fn is_true_when_even() {
-        assert!();
+        assert!(is_even(2));
     }
 
     #[test]
     fn is_false_when_odd() {
-        assert!();
+        assert!(!is_even(1));
     }
 }

exercises/threads/threads1.rs

@@ -6,9 +6,7 @@
 // of "waiting..." and the program ends without timing out when running,
 // you've got it :)
 
-// I AM NOT DONE
-
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
 
@@ -17,15 +15,15 @@ struct JobStatus {
 }
 
 fn main() {
-    let status = Arc::new(JobStatus { jobs_completed: 0 });
-    let status_shared = status.clone();
+    let status = Arc::new(Mutex::new(JobStatus { jobs_completed: 0 }));
+    let mut status_shared = status.clone();
     thread::spawn(move || {
         for _ in 0..10 {
             thread::sleep(Duration::from_millis(250));
-            status_shared.jobs_completed += 1;
+            status_shared.lock().unwrap().jobs_completed += 1;
         }
     });
-    while status.jobs_completed < 10 {
+    while status.lock().unwrap().jobs_completed < 10 {
         println!("waiting... ");
         thread::sleep(Duration::from_millis(500));
     }

exercises/traits/traits1.rs

@@ -8,14 +8,14 @@
 // which appends "Bar" to any object
 // implementing this trait.
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
-    //Add your code here
+    fn append_bar(self) -> Self {
+        self + "Bar"
+    }
 }
 
 fn main() {

exercises/traits/traits2.rs

@@ -10,13 +10,16 @@
 // No boiler plate code this time,
 // you can do this!
 
-// I AM NOT DONE
-
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
-//TODO: Add your code here
+impl AppendBar for Vec<String> {
+    fn append_bar(mut self) -> Self {
+        self.push("Bar".into());
+        self
+    }
+}
 
 #[cfg(test)]
 mod tests {

exercises/variables/variables1.rs

@@ -6,9 +6,7 @@
 // even after you already figured it out. If you got everything working and
 // feel ready for the next exercise, remove the `I AM NOT DONE` comment below.
 
-// I AM NOT DONE
-
 fn main() {
-    x = 5;
+    let x = 5;
     println!("x has the value {}", x);
 }

exercises/variables/variables2.rs

@@ -1,10 +1,8 @@
 // variables2.rs
 // Make me compile! Execute the command `rustlings hint variables2` if you want a hint :)
 
-// I AM NOT DONE
-
 fn main() {
-    let x;
+    let x: usize = 10;
     if x == 10 {
         println!("Ten!");
     } else {

exercises/variables/variables3.rs

@@ -1,10 +1,8 @@
 // variables3.rs
 // Make me compile! Execute the command `rustlings hint variables3` if you want 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/variables4.rs

@@ -1,9 +1,7 @@
 // variables4.rs
 // Make me compile! Execute the command `rustlings hint variables4` if you want a hint :)
 
-// I AM NOT DONE
-
 fn main() {
-    let x: i32;
+    let x: i32 = 10;
     println!("Number {}", x);
 }

exercises/variables/variables5.rs

@@ -1,11 +1,9 @@
 // variables5.rs
 // Make me compile! Execute the command `rustlings hint variables5` if you want a hint :)
 
-// I AM NOT DONE
-
 fn main() {
     let number = "T-H-R-E-E";
     println!("Spell a Number : {}", number);
-    number = 3;
+    let number = 3;
     println!("Number plus two is : {}", number + 2);
 }

exercises/variables/variables6.rs

@@ -1,9 +1,7 @@
 // variables6.rs
 // Make me compile! Execute the command `rustlings hint variables6` if you want a hint :)
 
-// I AM NOT DONE
-
-const NUMBER = 3;
+const NUMBER: usize = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }