rust/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-bound-non-const-specialized-bound.rs
2023-06-05 16:09:46 +00:00

59 lines
1.1 KiB
Rust

// Tests that trait bounds on specializing trait impls must be `~const` if the
// same bound is present on the default impl and is `~const` there.
#![feature(const_trait_impl)]
#![feature(rustc_attrs)]
#![feature(min_specialization)]
#[rustc_specialization_trait]
trait Specialize {}
#[const_trait]
trait Foo {}
#[const_trait]
trait Bar {
fn bar();
}
// bgr360: I was only able to exercise the code path that raises the
// "missing ~const qualifier" error by making this base impl non-const, even
// though that doesn't really make sense to do. As seen below, if the base impl
// is made const, rustc fails earlier with an overlapping impl failure.
impl<T> Bar for T
where
T: ~const Foo,
{
default fn bar() {}
}
impl<T> Bar for T
where
T: Foo, //~ ERROR missing `~const` qualifier
T: Specialize,
{
fn bar() {}
}
#[const_trait]
trait Baz {
fn baz();
}
impl<T> const Baz for T
where
T: ~const Foo,
{
default fn baz() {}
}
impl<T> const Baz for T //~ ERROR conflicting implementations of trait `Baz`
where
T: Foo,
T: Specialize,
{
fn baz() {}
}
fn main() {}