// 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. // // If you need help, open the corresponding README.md or run: rustlings hint as_ref_mut // 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(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(arg: T) -> usize { arg.as_ref().chars().count() } fn main() { let s = "Café au lait"; println!("{}", char_counter(s)); println!("{}", byte_counter(s)); } #[cfg(test)] mod tests { use super::*; #[test] fn different_counts() { let s = "Café au lait"; assert_ne!(char_counter(s), byte_counter(s)); } #[test] fn same_counts() { let s = "Cafe au lait"; assert_eq!(char_counter(s), byte_counter(s)); } #[test] fn different_counts_using_string() { let s = String::from("Café au lait"); assert_ne!(char_counter(s.clone()), byte_counter(s)); } #[test] fn same_counts_using_string() { let s = String::from("Cafe au lait"); assert_eq!(char_counter(s.clone()), byte_counter(s)); } }