// This is a Rust file. It is a plain text file with a `.rs` extension. // // Like most modern programming languages, Rust supports comments. You're looking at one right now! // Comments are ignored by the compiler; you can leverage them to annotate code with notes and // explanations. // There are various ways to write comments in Rust, each with its own purpose. // For now we'll stick to the most common one: the line comment. // Everything from `//` to the end of the line is considered a comment. // Exercises will include `TODO`, `todo!()` or `__` markers to draw your attention to the lines // where you need to write code. // You'll need to replace these markers with your own code to complete the exercise. // Sometimes it'll be enough to write a single line of code, other times you'll have to write // longer sections. // // If you get stuck for more than 10 minutes on an exercise, grab a trainer! We're here to help! // You can also find solutions to all exercises in the `solutions` git branch. fn greeting() -> &'static str { // TODO: fix me 👇 "I'm ready to learn Rust!" } // Your solutions will be automatically verified by a set of tests. // You can run these tests directly by invoking the `cargo test` command in your terminal, // from the root of this exercise's directory. That's what the `wr` command does for you // under the hood. // // Rust lets you write tests alongside your code. // The `#[cfg(test)]` attribute tells the compiler to only compile the code below when // running tests (i.e. when you run `cargo test`). // You'll learn more about attributes and testing later in the course. // For now, just know that you need to look for the `#[cfg(test)]` attribute to find the tests // that will be verifying the correctness of your solutions! // // ⚠️ **DO NOT MODIFY THE TESTS** ⚠️ // They are there to help you validate your solutions. You should only change the code that's being // tested, not the tests themselves. #[cfg(test)] mod tests { use crate::greeting; #[test] fn test_welcome() { assert_eq!(greeting(), "I'm ready to learn Rust!"); } }