I don't think this is correct; we really want `withUnsafePointer` on a global to produce the same address every time.

What provides this guarantee?

The language and compiler. I can't find a citation, but we've stated this publicly on multiple occasions, and recommended it as a pattern for KVO context IDs.

OK, what should we do with non-globals then?

It's not usually a pain to make those vars for this purpose. A little annoying, but not overly so.

It is not huge issue, but users are complaining about it. You also can't do this for APIs you don't own, so you have to introduce temporaries for no reason.

As I commented in apple/swift-evolution#437 for those cases where you don't care about getting the same address, I can see the convenience of having an API like withUnsafePointer that does not require an inout argument, but it would be better to introduce a new API with a different name for that purpose.

We discussed including this change in SE-0127 (https://github.com/apple/swift-evolution/blob/master/proposals/0127-cleaning-up-stdlib-ptr-buffer.md) and decided not to change the behavior of withUnsafePointer in Swift 3. However, we could still consider adding a separate variant in a future that works with immutable values.

Fixed in SE-0205 withUnsafePointer(to:🙂 and withUnsafeBytes(of:🙂 for immutable values