#![feature(const_trait_impl)] // revisions: yy yn ny nn #[cfg_attr(any(yy, yn), const_trait)] trait Foo { fn a(&self); } #[cfg_attr(any(yy, ny), const_trait)] trait Bar: ~const Foo {} //[ny,nn]~^ ERROR: ~const can only be applied to `#[const_trait]` //[ny,nn]~| ERROR: ~const can only be applied to `#[const_trait]` const fn foo(x: &T) { x.a(); //[yn,yy]~^ ERROR the trait bound } fn main() {}