Generic associated types in Rust 1.65

The Rust Types Team announcesthat the long-awaited generic associated types feature will be stable in Rust 1.65.

At its core, generic associated types allow you to have generics(type, lifetime, or const) on associated types. Note that this isreally just rounding out the places where you can put generics: forexample, you can already have generics on freestanding type aliasesand on functions in traits. Now you can just have generics on typealiases in traits (which we just call associated types).