[PATCH] D44539: [Sema][Objective-C] Add check to warn when property of objc type has assign attribute

[John McCall via Phabricator via cfe-commits]

rjmccall added a comment.

This isn't really an Objective-C user forum, but I'll try to summarize briefly.  `unsafe_unretained` is an unsafe version of `weak` — it's unsafe because it can be left dangling if the object is deallocated.  It's necessary for a small (and getting smaller every year) set of classes that don't support true weak references, and it can be useful as an optimization to avoid the performance overhead of reference counting.


Repository:
  rC Clang

https://reviews.llvm.org/D44539