mod core { mod ops { #[lang = "add"] pub trait Add<Rhs = Self> { type Output; fn add(self, rhs: Rhs) -> Self::Output; } } } pub fn foo<T: core::ops::Add<Output = i32>>(a: T) -> i32 { a + a } pub fn main() { foo(123f32); // { dg-error "bounds not satisfied for f32 .Add. is not satisfied" "" { target *-*-* } .-1 } }