#![feature(specialization)] //~ WARN the feature `specialization` is incomplete trait Foo { fn foo() {} } impl Foo for T {} impl Foo for Vec {} //~ ERROR E0119 trait Bar { fn bar() {} } impl Bar for (T, u8) {} impl Bar for (u8, T) {} //~ ERROR E0119 trait Baz { fn baz() {} } impl Baz for u8 {} impl Baz for T {} //~ ERROR E0119 trait Qux { fn qux() {} } impl Qux for T {} impl Qux for T {} //~ ERROR E0119 fn main() {}