rust-clippy/tests/ui/map_err.rs
2023-08-22 17:18:11 +02:00

30 lines
694 B
Rust

#![warn(clippy::map_err_ignore)]
#![allow(clippy::unnecessary_wraps)]
use std::error::Error;
use std::fmt;
#[derive(Debug)]
enum Errors {
Ignored,
}
impl Error for Errors {}
impl fmt::Display for Errors {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "Error")
}
}
fn main() -> Result<(), Errors> {
let x = u32::try_from(-123_i32);
println!("{:?}", x.map_err(|_| Errors::Ignored));
//~^ ERROR: `map_err(|_|...` wildcard pattern discards the original error
// Should not warn you because you explicitly ignore the parameter
// using a named wildcard value
println!("{:?}", x.map_err(|_foo| Errors::Ignored));
Ok(())
}