rust/tests/ui/lint/unused/unused-result.rs

43 lines
1.1 KiB
Rust

#![allow(dead_code)]
#![deny(unused_results, unused_must_use)]
//~^ NOTE: the lint level is defined here
//~| NOTE: the lint level is defined here
#[must_use]
enum MustUse { Test }
#[must_use = "some message"]
enum MustUseMsg { Test2 }
fn foo<T>() -> T { panic!() }
fn bar() -> isize { return foo::<isize>(); }
fn baz() -> MustUse { return foo::<MustUse>(); }
fn qux() -> MustUseMsg { return foo::<MustUseMsg>(); }
#[allow(unused_results)]
fn test() {
foo::<isize>();
foo::<MustUse>(); //~ ERROR: unused `MustUse` that must be used
foo::<MustUseMsg>(); //~ ERROR: unused `MustUseMsg` that must be used
//~^ NOTE: some message
}
#[allow(unused_results, unused_must_use)]
fn test2() {
foo::<isize>();
foo::<MustUse>();
foo::<MustUseMsg>();
}
fn main() {
foo::<isize>(); //~ ERROR: unused result of type `isize`
foo::<MustUse>(); //~ ERROR: unused `MustUse` that must be used
foo::<MustUseMsg>(); //~ ERROR: unused `MustUseMsg` that must be used
//~^ NOTE: some message
let _ = foo::<isize>();
let _ = foo::<MustUse>();
let _ = foo::<MustUseMsg>();
}