rust/tests/ui/redundant_pattern_matching_result.rs
Jason Newcomb b6581636bd
Improve redundant_pattern_matching
Add a note when the drop order change may result in different behaviour.
2021-04-15 20:37:15 -04:00

129 lines
2.5 KiB
Rust

// run-rustfix
#![warn(clippy::all)]
#![warn(clippy::redundant_pattern_matching)]
#![allow(
unused_must_use,
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::unnecessary_wraps,
deprecated,
clippy::if_same_then_else
)]
fn main() {
let result: Result<usize, usize> = Err(5);
if let Ok(_) = &result {}
if let Ok(_) = Ok::<i32, i32>(42) {}
if let Err(_) = Err::<i32, i32>(42) {}
while let Ok(_) = Ok::<i32, i32>(10) {}
while let Err(_) = Ok::<i32, i32>(10) {}
if Ok::<i32, i32>(42).is_ok() {}
if Err::<i32, i32>(42).is_err() {}
if let Ok(x) = Ok::<i32, i32>(42) {
println!("{}", x);
}
match Ok::<i32, i32>(42) {
Ok(_) => true,
Err(_) => false,
};
match Ok::<i32, i32>(42) {
Ok(_) => false,
Err(_) => true,
};
match Err::<i32, i32>(42) {
Ok(_) => false,
Err(_) => true,
};
match Err::<i32, i32>(42) {
Ok(_) => true,
Err(_) => false,
};
let _ = if let Ok(_) = Ok::<usize, ()>(4) { true } else { false };
issue5504();
issue6067();
issue6065();
let _ = if let Ok(_) = gen_res() {
1
} else if let Err(_) = gen_res() {
2
} else {
3
};
}
fn gen_res() -> Result<(), ()> {
Ok(())
}
macro_rules! m {
() => {
Some(42u32)
};
}
fn issue5504() {
fn result_opt() -> Result<Option<i32>, i32> {
Err(42)
}
fn try_result_opt() -> Result<i32, i32> {
while let Some(_) = r#try!(result_opt()) {}
if let Some(_) = r#try!(result_opt()) {}
Ok(42)
}
try_result_opt();
if let Some(_) = m!() {}
while let Some(_) = m!() {}
}
fn issue6065() {
macro_rules! if_let_in_macro {
($pat:pat, $x:expr) => {
if let Some($pat) = $x {}
};
}
// shouldn't be linted
if_let_in_macro!(_, Some(42));
}
// Methods that are unstable const should not be suggested within a const context, see issue #5697.
// However, in Rust 1.48.0 the methods `is_ok` and `is_err` of `Result` were stabilized as const,
// so the following should be linted.
const fn issue6067() {
if let Ok(_) = Ok::<i32, i32>(42) {}
if let Err(_) = Err::<i32, i32>(42) {}
while let Ok(_) = Ok::<i32, i32>(10) {}
while let Err(_) = Ok::<i32, i32>(10) {}
match Ok::<i32, i32>(42) {
Ok(_) => true,
Err(_) => false,
};
match Err::<i32, i32>(42) {
Ok(_) => false,
Err(_) => true,
};
}