Documentation Tests

Rust has built-in support for documentation tests:

1. #![allow(unused)]
2. fn main() {
3. /// Shortens a string to the given length.
4. ///
5. ///

/// use playground::shorten_string; /// assert_eq!(shorten_string(“Hello World”, 5), “Hello”); /// assert_eq!(shorten_string(“Hello World”, 20), “Hello World”); /// pub fn shorten_string(s: &str, length: usize) -> &str { &s[..std::cmp::min(length, s.len())] } }

• Code blocks in /// comments are automatically seen as Rust code.
• The code will be compiled and executed as part of cargo test.
• Test the above code on the Rust Playground.