//@ known-bug: #102498 #![feature(const_trait_impl, generic_const_exprs)] #[const_trait] pub trait Tr { fn a() -> usize; } impl Tr for () { fn a() -> usize { 1 } } const fn foo() -> [u8; T::a()] { [0; T::a()] } fn main() { foo::<()>(); }