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//@ known-bug: #110395
#![feature(const_trait_impl, min_specialization, rustc_attrs)]
#[rustc_specialization_trait]
#[const_trait]
pub unsafe trait Sup {
fn foo() -> u32;
}
#[rustc_specialization_trait]
#[const_trait]
pub unsafe trait Sub: ~const Sup {}
unsafe impl const Sup for u8 {
default fn foo() -> u32 {
1
}
}
unsafe impl const Sup for () {
fn foo() -> u32 {
42
}
}
unsafe impl const Sub for () {}
#[const_trait]
pub trait A {
fn a() -> u32;
}
impl<T: ~const Default> const A for T {
default fn a() -> u32 {
2
}
}
impl<T: ~const Default + ~const Sup> const A for T {
default fn a() -> u32 {
3
}
}
impl<T: ~const Default + ~const Sub> const A for T {
fn a() -> u32 {
T::foo()
}
}
const _: () = assert!(<()>::a() == 42);
const _: () = assert!(<u8>::a() == 3);
const _: () = assert!(<u16>::a() == 2);
fn main() {}
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