[PATCH] D19700: [libcxx] [test] nasty_mutex::operator& should return nullptr, like nasty_list above it.

[Stephan T. Lavavej via cfe-commits]

[Eric Fiselier] 
> Well arguable it should be `no return` or even better it should
> have an "= delete" so it's diagnosed even if it's not called.
> For now this works though.

Agreed - I just wasn't sure what this code was trying to do, and I figured it should be consistent. I'm trying to keep my patches minimally intrusive until I understand your tests better.

Thanks,
STL