[PATCH] D41048: [libcxx] workaround PR 28385 in __find_exactly_one_checked

[Casey Carter via Phabricator via cfe-commits]

CaseyCarter added a comment.

In https://reviews.llvm.org/D41048#950601, @mclow.lists wrote:

> These tests don't fail for me. (using a clang I built two days ago)


What about the repro for #35578 <https://bugs.llvm.org/show_bug.cgi?id=35578>? That repro and these four tests trigger the bug for me (...could not match "const bool" against "const bool") with clang version 6.0.0-svn320282-1~exp1 (trunk) freshly updated from apt.llvm.org on Ubuntu trusty running atop Windows Subsystem for Linux. (We've been shipping a workaround for 28385 <https://bugs.llvm.org/show_bug.cgi?id=28385> in MSFT `<variant>` forever, and in range-v3 for even longer <https://github.com/ericniebler/range-v3/blob/master/include/meta/meta.hpp#L1979>.) Both Godbolt <https://godbolt.org/g/zU11ck> and Wandbox <https://wandbox.org/permlink/7T2sHvBRWGpbO0q2> agree.


https://reviews.llvm.org/D41048