[swift-evolution] [Review] SE-0055 Make unsafe pointer nullability explicit using Optional

[Chris Lattner]

On Mar 24, 2016, at 7:28 PM, John McCall via swift-evolution <swift-evolution at swift.org> wrote:
> I'd actually be much more concerned about the pervasive assumptions about pointer representation in Clang and LLVM than I would be with Swift.
> 
> Now, it would probably be very annoying to support a platform where different pointer types had different null values, but the last of those died awhile ago, I believe.

The last significant one IIRC was Itanium, in the case of C++ member pointers (themselves an odd beast), which had a different representation than data pointers (-1 is null).

-Chris