rust/tests/ui/rfcs/rfc-2632-const-trait-impl/tilde-const-and-const-params.rs
Raekye 884af362f2 Validate ~const trait bounds on associated fns.
Previously, any associated function could have `~const` trait bounds on
generic parameters, which could lead to ICEs when these bounds were used
on associated functions of non-`#[const_trait] trait` or
non-`impl const` blocks.

Includes changes as per @fee1-dead's comments in #116210.
2023-09-30 19:00:45 -04:00

38 lines
769 B
Rust

#![feature(const_trait_impl, effects)]
#![feature(generic_arg_infer)]
#![feature(generic_const_exprs)]
#![allow(incomplete_features)]
struct Foo<const N: usize>;
impl<const N: usize> Foo<N> {
fn add<A: ~const Add42>(self) -> Foo<{ A::add(N) }> {
//~^ ERROR `~const` is not allowed here
//~| ERROR mismatched types
Foo
}
}
#[const_trait]
trait Add42 {
fn add(a: usize) -> usize;
}
impl const Add42 for () {
fn add(a: usize) -> usize {
a + 42
}
}
fn bar<A: ~const Add42, const N: usize>(_: Foo<N>) -> Foo<{ A::add(N) }> {
//~^ ERROR `~const` is not allowed here
//~| ERROR mismatched types
Foo
}
fn main() {
let foo = Foo::<0>;
let foo = bar::<(), _>(foo);
let _foo = bar::<(), _>(foo);
}