[all-commits] [llvm/llvm-project] eadece: [libcxx] adds common_reference to <type_traits>

[Christopher Di Bella via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: eadece333f6112502046fad0f2c062d13a37079b
      https://github.com/llvm/llvm-project/commit/eadece333f6112502046fad0f2c062d13a37079b
  Author: Christopher Di Bella <cjdb.ns at gmail.com>
  Date:   2021-03-02 (Tue, 02 Mar 2021)

  Changed paths:
    M libcxx/include/type_traits
    A libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_reference.compile.pass.cpp

  Log Message:
  -----------
  [libcxx] adds common_reference to <type_traits>

Implements part of P0898R3 Standard Library Concepts

Reworks D74351 to use requires-clauses over SFINAE and so that it more
closely follows the wording.

Co-authored by: Michael Schellenberger Costa <mschellenbergercosta at googlemail.com>

(Michael did all the heavy lifting and I came in to polish it for
 submission, since Michael is focussing on `std::format` now.)

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D96657