#![feature(const_trait_impl)] #![feature(const_fn_trait_bound)] // FIXME is this needed? trait ConstDefaultFn: Sized { fn b(self); #[default_method_body_is_const] fn a(self) { self.b(); } } struct NonConstImpl; struct ConstImpl; impl ConstDefaultFn for NonConstImpl { fn b(self) {} } impl const ConstDefaultFn for ConstImpl { fn b(self) {} } const fn test() { NonConstImpl.a(); //~^ ERROR calls in constant functions are limited to constant functions, tuple structs and tuple variants ConstImpl.a(); } fn main() {}