#![feature(never_type)] #![warn(clippy::result_map_unit_fn)] #![allow(unused)] fn do_nothing<T>(_: T) {} fn diverge<T>(_: T) -> ! { panic!() } fn plus_one(value: usize) -> usize { value + 1 } #[rustfmt::skip] fn result_map_unit_fn() { x.field.map(|value| { do_nothing(value); do_nothing(value) }); x.field.map(|value| if value > 0 { do_nothing(value); do_nothing(value) }); // Suggestion for the let block should be `{ ... }` as it's too difficult to build a // proper suggestion for these cases x.field.map(|value| { do_nothing(value); do_nothing(value) }); x.field.map(|value| { do_nothing(value); do_nothing(value); }); // The following should suggest `if let Ok(_X) ...` as it's difficult to generate a proper let variable name for them let res: Result<!, usize> = Ok(42).map(diverge); "12".parse::<i32>().map(diverge); let res: Result<(), usize> = Ok(plus_one(1)).map(do_nothing); // Should suggest `if let Ok(_y) ...` to not override the existing foo variable let y: Result<usize, usize> = Ok(42); y.map(do_nothing); } fn main() {}