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//@ revisions: nofallback fallback
//@[nofallback] run-pass
//@[fallback] check-fail
// We need to opt into the `never_type_fallback` feature
// to trigger the requirement that this is testing.
#![cfg_attr(fallback, feature(never_type, never_type_fallback))]
#![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) {}
//[fallback]~^ NOTE required by this bound in `foo`
//[fallback]~| NOTE required by a bound in `foo`
fn smeg() {
//[nofallback]~^ warn: this function depends on never type fallback being `()`
//[nofallback]~| warn: this was previously accepted by the compiler but is being phased out; it will become a hard error in Rust 2024 and in a future release in all editions!
let _x = return;
foo(_x);
//[fallback]~^ ERROR the trait bound
//[fallback]~| NOTE the trait `ImplementedForUnitButNotNever` is not implemented
//[fallback]~| HELP trait `ImplementedForUnitButNotNever` is implemented for `()`
//[fallback]~| NOTE this error might have been caused
//[fallback]~| NOTE required by a bound introduced by this call
//[fallback]~| HELP did you intend
}
fn main() {
smeg();
}
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