GAT: Constructing associated types parameterised by lifetime

[dhardy]

Uses generic associated types - #44265

As I understand it, the following should be legal:

trait A {
    type B<'a>;
    
    fn make_b<'a>(&'a self) -> Self::B<'a>;
}

I simply get an error:

error[E0109]: lifetime arguments are not allowed for this type
 --> src/lib.rs:6:40
  |
6 |     fn make_b<'a>(&'a self) -> Self::B<'a>;
  |                                        ^^ lifetime argument not allowed

Playground: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=a4a05477f9f0f529277707801ffd0297

[csmoe]

lifetime is not needed here -> Self::<'a>, just return Self::B.

[dhardy]

Then perhaps you'd like to fix this silly example?

[csmoe]

@dhardy sorry, my fault. Self::B works here because of lifetime elision, NOT unneeded actually