struct Foo<A, B>(A, B); impl Foo<i32, f32> { fn test<X>(self, a: X) -> X { a } } fn main() { let a; a = Foo(123, 456f32); let b; b = a.test::<asfasfr>(false); // { dg-error "failed to resolve TypePath: asfasfr" "" { target *-*-* } .-1 } }