Stream: t-compiler/help

Topic: GAT questions


Areredify (Mar 08 2020 at 14:21, on Zulip):

First question: the GAT rfc states that adding type HRTBs is not a part of it, but also states that type X<'a>: Y is the same as for<'a> Self::X<'a>: Y bound on the trait itself. I assume it means the same in case of type X<T>: Y which requires(?) type HRTBs (at least implementation wise), so I am a bit confused.
Second question: I believe the rfc doesn't mention bounds on the type constructor parameters (i.e. trait Trait<'b> { type X<'a: 'b>; }) , although there is a line that I don't understand that is maybe related:
"This RFC does not propose allowing any sort of bound by the type constructor itself, whether an equality bound or a trait bound (trait bounds of course are also impossible)."
Does that line mean that type constructor can't impose bounds on it's parameters? What about implicit bounds in type constructors parametrized by types?

Last update: Sep 27 2020 at 14:15UTC