repo stringlengths 6 65 | file_url stringlengths 81 311 | file_path stringlengths 6 227 | content stringlengths 0 32.8k | language stringclasses 1
value | license stringclasses 7
values | commit_sha stringlengths 40 40 | retrieved_at stringdate 2026-01-04 15:31:58 2026-01-04 20:25:31 | truncated bool 2
classes |
|---|---|---|---|---|---|---|---|---|
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/05_vecs/vecs1.rs | solutions/05_vecs/vecs1.rs | fn array_and_vec() -> ([i32; 4], Vec<i32>) {
let a = [10, 20, 30, 40]; // Array
// Used the `vec!` macro.
let v = vec![10, 20, 30, 40];
(a, v)
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_array_and_vec_similarity() {
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/05_vecs/vecs2.rs | solutions/05_vecs/vecs2.rs | fn vec_loop(input: &[i32]) -> Vec<i32> {
let mut output = Vec::new();
for element in input {
output.push(2 * element);
}
output
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_vec_loop() {
let input = [2, ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/14_generics/generics2.rs | solutions/14_generics/generics2.rs | struct Wrapper<T> {
value: T,
}
impl<T> Wrapper<T> {
fn new(value: T) -> Self {
Wrapper { value }
}
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn store_u32_in_wrapper() {
assert_eq!(Wrapper::new(42).value, 42);
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/14_generics/generics1.rs | solutions/14_generics/generics1.rs | // `Vec<T>` is generic over the type `T`. In most cases, the compiler is able to
// infer `T`, for example after pushing a value with a concrete type to the vector.
// But in this exercise, the compiler needs some help through a type annotation.
fn main() {
// `u8` and `i8` can both be converted to `i16`.
let ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/10_modules/modules1.rs | solutions/10_modules/modules1.rs | mod sausage_factory {
fn get_secret_recipe() -> String {
String::from("Ginger")
}
// Added `pub` before `fn` to make the function accessible outside the module.
pub fn make_sausage() {
get_secret_recipe();
println!("sausage!");
}
}
fn main() {
sausage_factory::make_saus... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/10_modules/modules3.rs | solutions/10_modules/modules3.rs | use std::time::{SystemTime, UNIX_EPOCH};
fn main() {
match SystemTime::now().duration_since(UNIX_EPOCH) {
Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()),
Err(_) => panic!("SystemTime before UNIX EPOCH!"),
}
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/10_modules/modules2.rs | solutions/10_modules/modules2.rs | mod delicious_snacks {
// Added `pub` and used the expected alias after `as`.
pub use self::fruits::PEAR as fruit;
pub use self::veggies::CUCUMBER as veggie;
mod fruits {
pub const PEAR: &str = "Pear";
pub const APPLE: &str = "Apple";
}
mod veggies {
pub const CUCUMBER:... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/quizzes/quiz2.rs | solutions/quizzes/quiz2.rs | // Let's build a little machine in the form of a function. As input, we're going
// to give a list of strings and commands. These commands determine what action
// is going to be applied to the string. It can either be:
// - Uppercase the string
// - Trim the string
// - Append "bar" to the string a specified amount of... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/quizzes/quiz3.rs | solutions/quizzes/quiz3.rs | // An imaginary magical school has a new report card generation system written
// in Rust! Currently, the system only supports creating report cards where the
// student's grade is represented numerically (e.g. 1.0 -> 5.5). However, the
// school also issues alphabetical grades (A+ -> F-) and needs to be able to
// pri... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/quizzes/quiz1.rs | solutions/quizzes/quiz1.rs | // Mary is buying apples. The price of an apple is calculated as follows:
// - An apple costs 2 rustbucks.
// - However, if Mary buys more than 40 apples, the price of each apple in the
// entire order is reduced to only 1 rustbuck!
fn calculate_price_of_apples(n_apples: u64) -> u64 {
if n_apples > 40 {
n_... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/16_lifetimes/lifetimes1.rs | solutions/16_lifetimes/lifetimes1.rs | // The Rust compiler needs to know how to check whether supplied references are
// valid, so that it can let the programmer know if a reference is at risk of
// going out of scope before it is used. Remember, references are borrows and do
// not own their own data. What if their owner goes out of scope?
fn longest<'a>... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/16_lifetimes/lifetimes3.rs | solutions/16_lifetimes/lifetimes3.rs | // Lifetimes are also needed when structs hold references.
struct Book<'a> {
// ^^^^ added a lifetime annotation
author: &'a str,
// ^^
title: &'a str,
// ^^
}
fn main() {
let book = Book {
author: "George Orwell",
title: "1984",
};
println!("{} by {}", ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/16_lifetimes/lifetimes2.rs | solutions/16_lifetimes/lifetimes2.rs | fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
if x.len() > y.len() { x } else { y }
}
fn main() {
let string1 = String::from("long string is long");
// Solution 1: You can move `strings2` out of the inner block so that it is
// not dropped before the print statement.
let string2 = String::fro... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/00_intro/intro1.rs | solutions/00_intro/intro1.rs | fn main() {
// Congratulations, you finished the first exercise 🎉
// As an introduction to Rustlings, the first exercise only required
// entering `n` in the terminal to go to the next exercise.
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/00_intro/intro2.rs | solutions/00_intro/intro2.rs | fn main() {
// `println!` instead of `printline!`.
println!("Hello world!");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/21_macros/macros4.rs | solutions/21_macros/macros4.rs | // Added semicolons to separate the macro arms.
#[rustfmt::skip]
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
($val:expr) => {
println!("Look at this other macro: {}", $val);
};
}
fn main() {
my_macro!();
my_macro!(7777);
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/21_macros/macros2.rs | solutions/21_macros/macros2.rs | // Moved the macro definition to be before its call.
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
fn main() {
my_macro!();
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/21_macros/macros1.rs | solutions/21_macros/macros1.rs | macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
fn main() {
my_macro!();
// ^
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/21_macros/macros3.rs | solutions/21_macros/macros3.rs | // Added the `macro_use` attribute.
#[macro_use]
mod macros {
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
}
fn main() {
my_macro!();
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/01_variables/variables5.rs | solutions/01_variables/variables5.rs | fn main() {
let number = "T-H-R-E-E";
println!("Spell a number: {number}");
// Using variable shadowing
// https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html#shadowing
let number = 3;
println!("Number plus two is: {}", number + 2);
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/01_variables/variables1.rs | solutions/01_variables/variables1.rs | fn main() {
// Declaring variables requires the `let` keyword.
let x = 5;
println!("x has the value {x}");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/01_variables/variables2.rs | solutions/01_variables/variables2.rs | fn main() {
// The easiest way to fix the compiler error is to initialize the
// variable `x`. By setting its value to an integer, Rust infers its type
// as `i32` which is the default type for integers.
let x = 42;
// But we can enforce a type different from the default `i32` by adding
// a ty... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/01_variables/variables6.rs | solutions/01_variables/variables6.rs | // The type of constants must always be annotated.
const NUMBER: u64 = 3;
fn main() {
println!("Number: {NUMBER}");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/01_variables/variables3.rs | solutions/01_variables/variables3.rs | #![allow(clippy::needless_late_init)]
fn main() {
// Reading uninitialized variables isn't allowed in Rust!
// Therefore, we need to assign a value first.
let x: i32 = 42;
println!("Number {x}");
// It is possible to declare a variable and initialize it later.
// But it can't be used before i... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/01_variables/variables4.rs | solutions/01_variables/variables4.rs | fn main() {
// In Rust, variables are immutable by default.
// Adding the `mut` keyword after `let` makes the declared variable mutable.
let mut x = 3;
println!("Number {x}");
x = 5;
println!("Number {x}");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/04_primitive_types/primitive_types3.rs | solutions/04_primitive_types/primitive_types3.rs | fn main() {
// An array with 100 elements of the value 42.
let a = [42; 100];
if a.len() >= 100 {
println!("Wow, that's a big array!");
} else {
println!("Meh, I eat arrays like that for breakfast.");
panic!("Array not big enough, more elements needed");
}
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/04_primitive_types/primitive_types1.rs | solutions/04_primitive_types/primitive_types1.rs | fn main() {
let is_morning = true;
if is_morning {
println!("Good morning!");
}
let is_evening = !is_morning;
if is_evening {
println!("Good evening!");
}
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/04_primitive_types/primitive_types6.rs | solutions/04_primitive_types/primitive_types6.rs | fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
#[test]
fn indexing_tuple() {
let numbers = (1, 2, 3);
// Tuple indexing syntax.
let second = numbers.1;
assert_eq!(second, 2, "This is not the 2nd number in the tuple!");
}
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/04_primitive_types/primitive_types2.rs | solutions/04_primitive_types/primitive_types2.rs | fn main() {
let my_first_initial = 'C';
if my_first_initial.is_alphabetic() {
println!("Alphabetical!");
} else if my_first_initial.is_numeric() {
println!("Numerical!");
} else {
println!("Neither alphabetic nor numeric!");
}
// Example with an emoji.
let your_chara... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/04_primitive_types/primitive_types4.rs | solutions/04_primitive_types/primitive_types4.rs | fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
#[test]
fn slice_out_of_array() {
let a = [1, 2, 3, 4, 5];
// 0 1 2 3 4 <- indices
// -------
// |
// +--- slice
// Note that the upper ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/04_primitive_types/primitive_types5.rs | solutions/04_primitive_types/primitive_types5.rs | fn main() {
let cat = ("Furry McFurson", 3.5);
// Destructuring the tuple.
let (name, age) = cat;
println!("{name} is {age} years old");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/02_functions/functions5.rs | solutions/02_functions/functions5.rs | fn square(num: i32) -> i32 {
// Removed the semicolon `;` at the end of the line below to implicitly return the result.
num * num
}
fn main() {
let answer = square(3);
println!("The square of 3 is {answer}");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/02_functions/functions2.rs | solutions/02_functions/functions2.rs | // The type of function arguments must be annotated.
// Added the type annotation `u64`.
fn call_me(num: u64) {
for i in 0..num {
println!("Ring! Call number {}", i + 1);
}
}
fn main() {
call_me(3);
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/02_functions/functions4.rs | solutions/02_functions/functions4.rs | fn is_even(num: i64) -> bool {
num % 2 == 0
}
// The return type must always be annotated.
fn sale_price(price: i64) -> i64 {
if is_even(price) {
price - 10
} else {
price - 3
}
}
fn main() {
let original_price = 51;
println!("Your sale price is {}", sale_price(original_price))... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/02_functions/functions1.rs | solutions/02_functions/functions1.rs | // Some function with the name `call_me` without arguments or a return value.
fn call_me() {
println!("Hello world!");
}
fn main() {
call_me();
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/02_functions/functions3.rs | solutions/02_functions/functions3.rs | fn call_me(num: u8) {
for i in 0..num {
println!("Ring! Call number {}", i + 1);
}
}
fn main() {
// `call_me` expects an argument.
call_me(5);
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/12_options/options3.rs | solutions/12_options/options3.rs | #[derive(Debug)]
struct Point {
x: i32,
y: i32,
}
fn main() {
let optional_point = Some(Point { x: 100, y: 200 });
// Solution 1: Matching over the `Option` (not `&Option`) but without moving
// out of the `Some` variant.
match optional_point {
Some(ref p) => println!("Coordinates are ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/12_options/options1.rs | solutions/12_options/options1.rs | // This function returns how much ice cream there is left in the fridge.
// If it's before 22:00 (24-hour system), then 5 scoops are left. At 22:00,
// someone eats it all, so no ice cream is left (value 0). Return `None` if
// `hour_of_day` is higher than 23.
fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
m... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/12_options/options2.rs | solutions/12_options/options2.rs | fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
#[test]
fn simple_option() {
let target = "rustlings";
let optional_target = Some(target);
// if-let
if let Some(word) = optional_target {
assert_eq!(word, target);
}
}
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/06_move_semantics/move_semantics4.rs | solutions/06_move_semantics/move_semantics4.rs | fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
#[test]
fn move_semantics4() {
let mut x = Vec::new();
let y = &mut x;
// `y` used here.
y.push(42);
// The mutable reference `y` is not used anymore,
// therefore a new reference c... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/06_move_semantics/move_semantics3.rs | solutions/06_move_semantics/move_semantics3.rs | fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
// ^^^ added
vec.push(88);
vec
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn move_semantics3() {
let vec0 = vec![22, 44, 66];
let vec1 = fill_vec(vec0);
as... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/06_move_semantics/move_semantics5.rs | solutions/06_move_semantics/move_semantics5.rs | #![allow(clippy::ptr_arg)]
// Borrows instead of taking ownership.
// It is recommended to use `&str` instead of `&String` here. But this is
// enough for now because we didn't handle strings yet.
fn get_char(data: &String) -> char {
data.chars().last().unwrap()
}
// Takes ownership instead of borrowing.
fn strin... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/06_move_semantics/move_semantics2.rs | solutions/06_move_semantics/move_semantics2.rs | fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let mut vec = vec;
vec.push(88);
vec
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn move_semantics2() {
let vec0 = vec![22, 44, 66];
// Cloning `vec0` so that the clone is... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/solutions/06_move_semantics/move_semantics1.rs | solutions/06_move_semantics/move_semantics1.rs | fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
let mut vec = vec;
// ^^^ added
vec.push(88);
vec
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn move_semantics1() {
let vec0 = vec![22, 44, 66];
let vec1 = fill_vec(v... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/info_file.rs | src/info_file.rs | use anyhow::{Context, Error, Result, bail};
use serde::Deserialize;
use std::{fs, io::ErrorKind};
use crate::{embedded::EMBEDDED_FILES, exercise::RunnableExercise};
/// Deserialized from the `info.toml` file.
#[derive(Deserialize)]
pub struct ExerciseInfo {
/// Exercise's unique name.
pub name: String,
//... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/dev.rs | src/dev.rs | use anyhow::{Context, Result, bail};
use clap::Subcommand;
use std::path::PathBuf;
mod check;
mod new;
mod update;
#[derive(Subcommand)]
pub enum DevCommands {
/// Create a new project for community exercises
New {
/// The path to create the project in
path: PathBuf,
/// Don't try to i... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/cargo_toml.rs | src/cargo_toml.rs | use anyhow::{Context, Result};
use std::path::Path;
use crate::{exercise::RunnableExercise, info_file::ExerciseInfo};
/// Initial capacity of the bins buffer.
pub const BINS_BUFFER_CAPACITY: usize = 1 << 14;
/// Return the start and end index of the content of the list `bin = […]`.
/// bin = [xxxxxxxxxxxxxxxxx]
/// ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/list.rs | src/list.rs | use anyhow::{Context, Result};
use crossterm::{
QueueableCommand, cursor,
event::{
self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyEventKind, MouseEventKind,
},
terminal::{
DisableLineWrap, EnableLineWrap, EnterAlternateScreen, LeaveAlternateScreen,
disable_raw_... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/exercise.rs | src/exercise.rs | use anyhow::Result;
use crossterm::{
QueueableCommand,
style::{Attribute, Color, ResetColor, SetAttribute, SetForegroundColor},
};
use std::io::{self, StdoutLock, Write};
use crate::{
cmd::CmdRunner,
term::{self, CountedWrite, file_path, terminal_file_link, write_ansi},
};
/// The initial capacity of ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/app_state.rs | src/app_state.rs | use anyhow::{Context, Error, Result, bail};
use crossterm::{QueueableCommand, cursor, terminal};
use std::{
collections::HashSet,
env,
fs::{File, OpenOptions},
io::{Read, Seek, StdoutLock, Write},
path::{MAIN_SEPARATOR_STR, Path},
process::{Command, Stdio},
sync::{
atomic::{AtomicUsi... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/watch.rs | src/watch.rs | use anyhow::{Error, Result};
use notify::{Config, RecommendedWatcher, RecursiveMode, Watcher};
use std::{
io::{self, Write},
path::Path,
sync::{
atomic::{AtomicBool, Ordering::Relaxed},
mpsc::channel,
},
time::Duration,
};
use crate::{
app_state::{AppState, ExercisesProgress},
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/run.rs | src/run.rs | use anyhow::Result;
use crossterm::{
QueueableCommand,
style::{Color, ResetColor, SetForegroundColor},
};
use std::{
io::{self, Write},
process::ExitCode,
};
use crate::{
app_state::{AppState, ExercisesProgress},
exercise::{OUTPUT_CAPACITY, RunnableExercise, solution_link_line},
};
pub fn run(... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/init.rs | src/init.rs | use anyhow::{Context, Result, bail};
use crossterm::{
QueueableCommand,
style::{Attribute, Color, ResetColor, SetAttribute, SetForegroundColor},
};
use serde::Deserialize;
use std::{
env::set_current_dir,
fs::{self, create_dir},
io::{self, Write},
path::{Path, PathBuf},
process::{Command, St... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/embedded.rs | src/embedded.rs | use anyhow::{Context, Error, Result};
use std::{
fs::{self, create_dir},
io,
};
use crate::info_file::ExerciseInfo;
/// Contains all embedded files.
pub static EMBEDDED_FILES: EmbeddedFiles = rustlings_macros::include_files!();
// Files related to one exercise.
struct ExerciseFiles {
// The content of th... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/main.rs | src/main.rs | use anyhow::{Context, Result, bail};
use app_state::StateFileStatus;
use clap::{Parser, Subcommand};
use std::{
io::{self, IsTerminal, Write},
path::Path,
process::ExitCode,
};
use term::{clear_terminal, press_enter_prompt};
use self::{app_state::AppState, dev::DevCommands, info_file::InfoFile};
mod app_s... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/term.rs | src/term.rs | use crossterm::{
Command, QueueableCommand,
cursor::MoveTo,
style::{Attribute, Color, ResetColor, SetAttribute, SetForegroundColor},
terminal::{Clear, ClearType},
};
use std::{
fmt, fs,
io::{self, BufRead, StdoutLock, Write},
};
use crate::app_state::CheckProgress;
pub struct MaxLenWriter<'a, ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/cmd.rs | src/cmd.rs | use anyhow::{Context, Result, bail};
use serde::Deserialize;
use std::{
io::{Read, pipe},
path::PathBuf,
process::{Command, Stdio},
};
/// Run a command with a description for a possible error and append the merged stdout and stderr.
/// The boolean in the returned `Result` is true if the command's exit st... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/dev/update.rs | src/dev/update.rs | use anyhow::{Context, Result};
use std::fs;
use crate::{
cargo_toml::updated_cargo_toml,
info_file::{ExerciseInfo, InfoFile},
};
// Update the `Cargo.toml` file.
fn update_cargo_toml(
exercise_infos: &[ExerciseInfo],
cargo_toml_path: &str,
exercise_path_prefix: &[u8],
) -> Result<()> {
let cur... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/dev/check.rs | src/dev/check.rs | use anyhow::{Context, Error, Result, anyhow, bail};
use std::{
cmp::Ordering,
collections::HashSet,
fs::{self, OpenOptions, read_dir},
io::{self, Read, Write},
path::{Path, PathBuf},
process::{Command, Stdio},
thread,
};
use crate::{
CURRENT_FORMAT_VERSION,
cargo_toml::{BINS_BUFFER_... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/dev/new.rs | src/dev/new.rs | use anyhow::{Context, Result, bail};
use std::{
env::set_current_dir,
fs::{self, create_dir},
path::Path,
process::Command,
};
use crate::{CURRENT_FORMAT_VERSION, init::RUST_ANALYZER_TOML};
// Create a directory relative to the current directory and print its path.
fn create_rel_dir(dir_name: &str, cu... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/list/scroll_state.rs | src/list/scroll_state.rs | pub struct ScrollState {
n_rows: usize,
max_n_rows_to_display: usize,
selected: Option<usize>,
offset: usize,
scroll_padding: usize,
max_scroll_padding: usize,
}
impl ScrollState {
pub fn new(n_rows: usize, selected: Option<usize>, max_scroll_padding: usize) -> Self {
Self {
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/list/state.rs | src/list/state.rs | use anyhow::{Context, Result};
use crossterm::{
QueueableCommand,
cursor::{MoveTo, MoveToNextLine},
style::{
Attribute, Attributes, Color, ResetColor, SetAttribute, SetAttributes, SetForegroundColor,
},
terminal::{self, BeginSynchronizedUpdate, Clear, ClearType, EndSynchronizedUpdate},
};
us... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/watch/notify_event.rs | src/watch/notify_event.rs | use anyhow::{Context, Result};
use notify::{
Event, EventKind,
event::{AccessKind, AccessMode, MetadataKind, ModifyKind, RenameMode},
};
use std::{
sync::{
atomic::Ordering::Relaxed,
mpsc::{RecvTimeoutError, Sender, SyncSender, sync_channel},
},
thread,
time::Duration,
};
use su... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/watch/state.rs | src/watch/state.rs | use anyhow::{Context, Result};
use crossterm::{
QueueableCommand,
style::{
Attribute, Attributes, Color, ResetColor, SetAttribute, SetAttributes, SetForegroundColor,
},
terminal,
};
use std::{
io::{self, Read, StdoutLock, Write},
sync::mpsc::{Sender, SyncSender, sync_channel},
thread... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/src/watch/terminal_event.rs | src/watch/terminal_event.rs | use crossterm::event::{self, Event, KeyCode, KeyEventKind};
use std::sync::{
atomic::Ordering::Relaxed,
mpsc::{Receiver, Sender},
};
use super::{EXERCISE_RUNNING, WatchEvent};
pub enum InputEvent {
Next,
Run,
Hint,
List,
CheckAll,
Reset,
Quit,
}
pub fn terminal_event_handler(
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/tests/integration_tests.rs | tests/integration_tests.rs | use std::{
env::{self, consts::EXE_SUFFIX},
process::{Command, Stdio},
str::from_utf8,
};
enum Output<'a> {
FullStdout(&'a str),
PartialStdout(&'a str),
PartialStderr(&'a str),
}
use Output::*;
#[derive(Default)]
struct Cmd<'a> {
current_dir: Option<&'a str>,
args: &'a [&'a str],
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/tests/test_exercises/exercises/test_success.rs | tests/test_exercises/exercises/test_success.rs | fn main() {
println!("Output from `main` function");
}
#[cfg(test)]
mod tests {
#[test]
fn passes() {}
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/tests/test_exercises/exercises/test_failure.rs | tests/test_exercises/exercises/test_failure.rs | fn main() {}
#[cfg(test)]
mod tests {
#[test]
fn fails() {
assert!(false);
}
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/tests/test_exercises/exercises/compilation_failure.rs | tests/test_exercises/exercises/compilation_failure.rs | fn main() {
let
} | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/tests/test_exercises/exercises/compilation_success.rs | tests/test_exercises/exercises/compilation_success.rs | fn main() {}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/tests/test_exercises/exercises/not_in_info.rs | tests/test_exercises/exercises/not_in_info.rs | fn main() {}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/19_smart_pointers/cow1.rs | exercises/19_smart_pointers/cow1.rs | // This exercise explores the `Cow` (Clone-On-Write) smart pointer. It can
// enclose and provide immutable access to borrowed data and clone the data
// lazily when mutation or ownership is required. The type is designed to work
// with general borrowed data via the `Borrow` trait.
use std::borrow::Cow;
fn abs_all(i... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/19_smart_pointers/box1.rs | exercises/19_smart_pointers/box1.rs | // At compile time, Rust needs to know how much space a type takes up. This
// becomes problematic for recursive types, where a value can have as part of
// itself another value of the same type. To get around the issue, we can use a
// `Box` - a smart pointer used to store data on the heap, which also allows us
// to ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/19_smart_pointers/arc1.rs | exercises/19_smart_pointers/arc1.rs | // In this exercise, we are given a `Vec` of `u32` called `numbers` with values
// ranging from 0 to 99. We would like to use this set of numbers within 8
// different threads simultaneously. Each thread is going to get the sum of
// every eighth value with an offset.
//
// The first thread (offset 0), will sum 0, 8, 1... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/19_smart_pointers/rc1.rs | exercises/19_smart_pointers/rc1.rs | // In this exercise, we want to express the concept of multiple owners via the
// `Rc<T>` type. This is a model of our solar system - there is a `Sun` type and
// multiple `Planet`s. The planets take ownership of the sun, indicating that
// they revolve around the sun.
use std::rc::Rc;
#[derive(Debug)]
struct Sun;
#... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/22_clippy/clippy1.rs | exercises/22_clippy/clippy1.rs | // The Clippy tool is a collection of lints to analyze your code so you can
// catch common mistakes and improve your Rust code.
//
// For these exercises, the code will fail to compile when there are Clippy
// warnings. Check Clippy's suggestions from the output to solve the exercise.
fn main() {
// TODO: Fix the... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/22_clippy/clippy3.rs | exercises/22_clippy/clippy3.rs | // Here are some more easy Clippy fixes so you can see its utility.
// TODO: Fix all the Clippy lints.
#[allow(unused_variables, unused_assignments)]
fn main() {
let my_option: Option<&str> = None;
// Assume that you don't know the value of `my_option`.
// In the case of `Some`, we want to print its value.... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/22_clippy/clippy2.rs | exercises/22_clippy/clippy2.rs | fn main() {
let mut res = 42;
let option = Some(12);
// TODO: Fix the Clippy lint.
for x in option {
res += x;
}
println!("{res}");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/09_strings/strings1.rs | exercises/09_strings/strings1.rs | // TODO: Fix the compiler error without changing the function signature.
fn current_favorite_color() -> String {
"blue"
}
fn main() {
let answer = current_favorite_color();
println!("My current favorite color is {answer}");
}
| rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/09_strings/strings2.rs | exercises/09_strings/strings2.rs | // TODO: Fix the compiler error in the `main` function without changing this function.
fn is_a_color_word(attempt: &str) -> bool {
attempt == "green" || attempt == "blue" || attempt == "red"
}
fn main() {
let word = String::from("green"); // Don't change this line.
if is_a_color_word(word) {
print... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/09_strings/strings3.rs | exercises/09_strings/strings3.rs | fn trim_me(input: &str) -> &str {
// TODO: Remove whitespace from both ends of a string.
}
fn compose_me(input: &str) -> String {
// TODO: Add " world!" to the string! There are multiple ways to do this.
}
fn replace_me(input: &str) -> String {
// TODO: Replace "cars" in the string with "balloons".
}
fn ... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/09_strings/strings4.rs | exercises/09_strings/strings4.rs | // Calls of this function should be replaced with calls of `string_slice` or `string`.
fn placeholder() {}
fn string_slice(arg: &str) {
println!("{arg}");
}
fn string(arg: String) {
println!("{arg}");
}
// TODO: Here are a bunch of values - some are `String`, some are `&str`.
// Your task is to replace `plac... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/20_threads/threads3.rs | exercises/20_threads/threads3.rs | use std::{sync::mpsc, thread, time::Duration};
struct Queue {
first_half: Vec<u32>,
second_half: Vec<u32>,
}
impl Queue {
fn new() -> Self {
Self {
first_half: vec![1, 2, 3, 4, 5],
second_half: vec![6, 7, 8, 9, 10],
}
}
}
fn send_tx(q: Queue, tx: mpsc::Sender<u... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/20_threads/threads2.rs | exercises/20_threads/threads2.rs | // Building on the last exercise, we want all of the threads to complete their
// work. But this time, the spawned threads need to be in charge of updating a
// shared value: `JobStatus.jobs_done`
use std::{sync::Arc, thread, time::Duration};
struct JobStatus {
jobs_done: u32,
}
fn main() {
// TODO: `Arc` is... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/20_threads/threads1.rs | exercises/20_threads/threads1.rs | // This program spawns multiple threads that each runs for at least 250ms, and
// each thread returns how much time it took to complete. The program should
// wait until all the spawned threads have finished and should collect their
// return values into a vector.
use std::{
thread,
time::{Duration, Instant},
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/13_error_handling/errors2.rs | exercises/13_error_handling/errors2.rs | // Say we're writing a game where you can buy items with tokens. All items cost
// 5 tokens, and whenever you purchase items there is a processing fee of 1
// token. A player of the game will type in how many items they want to buy, and
// the `total_cost` function will calculate the total cost of the items. Since
// t... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/13_error_handling/errors6.rs | exercises/13_error_handling/errors6.rs | // Using catch-all error types like `Box<dyn Error>` isn't recommended for
// library code where callers might want to make decisions based on the error
// content instead of printing it out or propagating it further. Here, we define
// a custom error type to make it possible for callers to decide what to do next
// wh... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/13_error_handling/errors3.rs | exercises/13_error_handling/errors3.rs | // This is a program that is trying to use a completed version of the
// `total_cost` function from the previous exercise. It's not working though!
// Why not? What should we do to fix it?
use std::num::ParseIntError;
// Don't change this function.
fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/13_error_handling/errors1.rs | exercises/13_error_handling/errors1.rs | // TODO: This function refuses to generate text to be printed on a nametag if
// you pass it an empty string. It'd be nicer if it explained what the problem
// was instead of just returning `None`. Thankfully, Rust has a similar
// construct to `Option` that can be used to express error conditions. Change
// the functi... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/13_error_handling/errors4.rs | exercises/13_error_handling/errors4.rs | #[derive(PartialEq, Debug)]
enum CreationError {
Negative,
Zero,
}
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<Self, CreationError> {
// TODO: This function shouldn't always return an `Ok`.
// Read the tests bel... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/13_error_handling/errors5.rs | exercises/13_error_handling/errors5.rs | // This exercise is an altered version of the `errors4` exercise. It uses some
// concepts that we won't get to until later in the course, like `Box` and the
// `From` trait. It's not important to understand them in detail right now, but
// you can read ahead if you like. For now, think of the `Box<dyn ???>` type as
//... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/23_conversions/from_str.rs | exercises/23_conversions/from_str.rs | // This is similar to the previous `from_into` exercise. But this time, we'll
// implement `FromStr` and return errors instead of falling back to a default
// value. Additionally, upon implementing `FromStr`, you can use the `parse`
// method on strings to generate an object of the implementor type. You can read
// mor... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/23_conversions/try_from_into.rs | exercises/23_conversions/try_from_into.rs | // `TryFrom` is a simple and safe type conversion that may fail in a controlled
// way under some circumstances. Basically, this is the same as `From`. The main
// difference is that this should return a `Result` type instead of the target
// type itself. You can read more about it in the documentation:
// https://doc.... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/23_conversions/using_as.rs | exercises/23_conversions/using_as.rs | // Type casting in Rust is done via the usage of the `as` operator.
// Note that the `as` operator is not only used when type casting. It also helps
// with renaming imports.
fn average(values: &[f64]) -> f64 {
let total = values.iter().sum::<f64>();
// TODO: Make a conversion before dividing.
total / valu... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/23_conversions/from_into.rs | exercises/23_conversions/from_into.rs | // The `From` trait is used for value-to-value conversions. If `From` is
// implemented, an implementation of `Into` is automatically provided.
// You can read more about it in the documentation:
// https://doc.rust-lang.org/std/convert/trait.From.html
#[derive(Debug)]
struct Person {
name: String,
age: u8,
}
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/23_conversions/as_ref_mut.rs | exercises/23_conversions/as_ref_mut.rs | // AsRef and AsMut allow for cheap reference-to-reference conversions. 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.
// Obtain the number of bytes (not characters) in the given argument
// (`.len()` returns... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/07_structs/structs1.rs | exercises/07_structs/structs1.rs | struct ColorRegularStruct {
// TODO: Add the fields that the test `regular_structs` expects.
// What types should the fields have? What are the minimum and maximum values for RGB colors?
}
struct ColorTupleStruct(/* TODO: Add the fields that the test `tuple_structs` expects */);
#[derive(Debug)]
struct UnitSt... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/07_structs/structs2.rs | exercises/07_structs/structs2.rs | #[derive(Debug)]
struct Order {
name: String,
year: u32,
made_by_phone: bool,
made_by_mobile: bool,
made_by_email: bool,
item_number: u32,
count: u32,
}
fn create_order_template() -> Order {
Order {
name: String::from("Bob"),
year: 2019,
made_by_phone: false,
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/07_structs/structs3.rs | exercises/07_structs/structs3.rs | // Structs contain data, but can also have logic. In this exercise, we have
// defined the `Package` struct, and we want to test some logic attached to it.
#[derive(Debug)]
struct Package {
sender_country: String,
recipient_country: String,
weight_in_grams: u32,
}
impl Package {
fn new(sender_country:... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
rust-lang/rustlings | https://github.com/rust-lang/rustlings/blob/7850a73d95c02840f4ab3bf8d9571b08410e5467/exercises/17_tests/tests1.rs | exercises/17_tests/tests1.rs | // Tests are important to ensure that your code does what you think it should
// do.
fn is_even(n: i64) -> bool {
n % 2 == 0
}
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
// TODO: Import `is_even`. You can use a wildcard to import everything in
// the outer module.
... | rust | MIT | 7850a73d95c02840f4ab3bf8d9571b08410e5467 | 2026-01-04T15:31:58.719144Z | false |
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