rust/tests/ui/traits/const-traits/specializing-constness.rs

32 lines
497 B
Rust

#![feature(const_trait_impl, min_specialization, rustc_attrs)]
#[rustc_specialization_trait]
#[const_trait]
pub trait Sup {}
impl const Sup for () {}
#[const_trait]
pub trait A {
fn a() -> u32;
}
#[const_trait]
pub trait Spec {}
impl<T: ~const Spec> const A for T {
default fn a() -> u32 {
2
}
}
impl<T: Spec + Sup> A for T {
//~^ ERROR: cannot specialize
//FIXME(const_trait_impl) ~| ERROR: missing `~const` qualifier
fn a() -> u32 {
3
}
}
fn main() {}