1 // check-pass
2 // edition:2018
3
4 #![feature(generic_associated_types)]
5 #![feature(type_alias_impl_trait)]
6
7 use std::future::Future;
8
9 trait SearchableResource<Criteria> {
10 type SearchResult;
11 }
12
13 trait SearchableResourceExt<Criteria>: SearchableResource<Criteria> {
14 type Future<'f, A: 'f + ?Sized, B: 'f>: Future<Output = Result<Vec<A::SearchResult>, ()>> + 'f
15 where
16 A: SearchableResource<B>,
17 Self: 'f;
18
search<'c>(&'c self, client: &'c ()) -> Self::Future<'c, Self, Criteria>19 fn search<'c>(&'c self, client: &'c ()) -> Self::Future<'c, Self, Criteria>;
20 }
21
22 type SearchFutureTy<'f, A, B: 'f>
23 where
24 A: SearchableResource<B> + ?Sized + 'f,
25 = impl Future<Output = Result<Vec<A::SearchResult>, ()>> + 'f;
26 impl<T, Criteria> SearchableResourceExt<Criteria> for T
27 where
28 T: SearchableResource<Criteria>,
29 {
30 type Future<'f, A, B: 'f>
31 where
32 A: SearchableResource<B> + ?Sized + 'f,
33 Self: 'f,
34 = SearchFutureTy<'f, A, B>;
35
search<'c>(&'c self, _client: &'c ()) -> Self::Future<'c, Self, Criteria>36 fn search<'c>(&'c self, _client: &'c ()) -> Self::Future<'c, Self, Criteria> {
37 async move { todo!() }
38 }
39 }
40
main()41 fn main() {}
42