Support trait upcasting

Open lowr opened this issue 2 years ago • 2 comments

This PR implements RFC3324, dyn Trait upcasting (cc rust-lang/rust#65991).

As explained in the RFC, this PR adds builtin clauses for Unsize with applicability checks:

// when Trait2 is a super trait of Trait1 and AutoY is a subset of AutoX:
dyn Trait1 + AutoX + 'a: Unsize<dyn Trait2 + AutoY + 'b> :- EqGoal(...), 'a: 'b.

May 04 '23 10:05 lowr

This one I'll have to get back to

Jun 13 '23 17:06 jackh726

:umbrella: The latest upstream changes (presumably #780) made this pull request unmergeable. Please resolve the merge conflicts.

Jun 13 '23 17:06 bors