// Test that `rustc_specialization_trait` requires always applicable impls. #![feature(min_specialization)] #![feature(rustc_attrs)] #[rustc_specialization_trait] trait SpecMarker { fn f(); } impl SpecMarker for &'static u8 { //~^ ERROR cannot specialize fn f() {} } impl SpecMarker for (T, T) { //~^ ERROR specializing impl fn f() {} } impl SpecMarker for [T] { //~^ ERROR cannot specialize fn f() {} } fn main() {}