rust/src/test/ui/defaulted-never-note.rs
2019-04-22 16:57:01 +01:00

35 lines
710 B
Rust

// We need to opt into the `!` feature in order to trigger the
// requirement that this is testing.
#![feature(never_type)]
#![allow(unused)]
trait Deserialize: Sized {
fn deserialize() -> Result<Self, String>;
}
impl Deserialize for () {
fn deserialize() -> Result<(), String> {
Ok(())
}
}
trait ImplementedForUnitButNotNever {}
impl ImplementedForUnitButNotNever for () {}
fn foo<T: ImplementedForUnitButNotNever>(_t: T) {}
//~^ NOTE required by `foo`
fn smeg() {
let _x = return;
foo(_x);
//~^ ERROR the trait bound
//~| NOTE the trait `ImplementedForUnitButNotNever` is not implemented
//~| NOTE the trait is implemented for `()`
}
fn main() {
smeg();
}