# 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 use crate::chainerror::*; {{#include ../examples/tutorial4.rs:2:}} # #[allow(dead_code)] # mod chainerror { {{#includecomment ../src/lib.rs}} # } ~~~