tree 65ca3dc10de41ec0b69435b1b744350880cae808
parent 4f4883c11cf5b3a9c62df11c6851383348498ed0
author Arthur O'Dwyer <arthur.j.odwyer@gmail.com> 1607215061 -0500
committer Copybara-Service <copybara-worker@google.com> 1613725532 -0800

[libc++] [LWG2993] reference_wrapper<T> conversion from U&&

Implement the resolution of LWG2993. Replace a deleted constructor
with a constructor that SFINAEs away in appropriate circumstances.
Also, now that the constructor is templated, we must have an
explicit deduction guide to make CTAD work.

Some tests have been merged in from Agustín Bergé's D40259.

Differential Revision: https://reviews.llvm.org/D92725

GitOrigin-RevId: eec04092d67b94f47439a9065b6bd4cd60165be2