rust/src/test/ui/impl-trait/bound-normalization-fail.rs
2019-08-02 02:44:35 +01:00

52 lines
1,014 B
Rust

// compile-fail
// edition:2018
#![feature(async_await)]
#![feature(impl_trait_in_bindings)]
//~^ WARNING the feature `impl_trait_in_bindings` is incomplete
// See issue 60414
/////////////////////////////////////////////
// Reduction to `impl Trait`
struct Foo<T>(T);
trait FooLike { type Output; }
impl<T> FooLike for Foo<T> {
type Output = T;
}
mod impl_trait {
use super::*;
trait Trait {
type Assoc;
}
/// `T::Assoc` can't be normalized any further here.
fn foo_fail<T: Trait>() -> impl FooLike<Output=T::Assoc> {
//~^ ERROR: type mismatch
Foo(())
}
}
/////////////////////////////////////////////
// Same with lifetimes in the trait
mod lifetimes {
use super::*;
trait Trait<'a> {
type Assoc;
}
/// Missing bound constraining `Assoc`, `T::Assoc` can't be normalized further.
fn foo2_fail<'a, T: Trait<'a>>() -> impl FooLike<Output=T::Assoc> {
//~^ ERROR: type mismatch
Foo(())
}
}
fn main() {}