1 #![feature(generic_associated_types)] 2 3 trait Provider { 4 type A<'a>; 5 } 6 7 impl Provider for () { 8 type A<'a> = (); 9 } 10 11 struct Holder<B> { 12 inner: Box<dyn Provider<A = B>>, 13 //~^ ERROR: missing generics for associated type 14 } 15 main()16fn main() { 17 Holder { 18 inner: Box::new(()), 19 }; 20 } 21