[PATCH] D73245: Don't define std::max_align_t if not used in C++03 mode

Thu Jan 30 16:59:50 PST 2020

joerg added a comment.

Let me clarify the situation for a moment:
(1) libc++ does try to work in C++03 mode. See the separate implementation of <functional> for pre-C++11. It is also desirable to support. This is completely beside the question of TR1 support.
(2) The only reason why max_align_t is currently necessary is because it is used as default alignment in <new>.
(3) Most compilers we care about already have a preprocessor symbol specifically for that purpose.

If (3) is present, we shouldn't pollute the global namespace, especially with a potentially bogus value. Ideally, this shouldn't be necessary at all, since overaligned new doesn't exist in C++03. But that would be a much more intrusive change to <new> and go beyond "try not to break c++03".

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73245/new/

https://reviews.llvm.org/D73245