# Saving coding chars Because decorating an error with more information should not let you jump through hoops, `chainerror` has a quick macro for that. `mstrerror!()` fits right into `.map_err()` letting you quickly add more debug strings. `mstrerror!()` even understands `format!()` syntax like `println!()`. ~~~rust {{#include ../examples/tutorial4.rs}} # #[allow(dead_code)] # mod chainerror { {{#rustdoc_include ../src/lib.rs:-1}} # } ~~~