[all-commits] [llvm/llvm-project] 8ce267: [libc++][compare] Implement three_way_comparable[_...

[Ruslan Arutyunyan via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8ce2675b1363ea0afa160e5fc564199857e8506c
      https://github.com/llvm/llvm-project/commit/8ce2675b1363ea0afa160e5fc564199857e8506c
  Author: Ruslan Arutyunyan <ruslan.arutyunyan at intel.com>
  Date:   2021-09-05 (Sun, 05 Sep 2021)

  Changed paths:
    M libcxx/include/CMakeLists.txt
    A libcxx/include/__compare/three_way_comparable.h
    M libcxx/include/compare
    M libcxx/include/module.modulemap
    A libcxx/test/libcxx/diagnostics/detail.headers/compare/three_way_comparable.module.verify.cpp
    A libcxx/test/std/language.support/cmp/cmp.concept/three_way_comparable.compile.pass.cpp
    A libcxx/test/std/language.support/cmp/cmp.concept/three_way_comparable_with.compile.pass.cpp

  Log Message:
  -----------
  [libc++][compare] Implement three_way_comparable[_with] concepts

Implementation of `three_way_comparable` and `three_way_comparable_with` concepts from <compare> header.

Please note that I have temporarily removed `<compare>` header from `<utility>` due to cyclic dependency that prevents using `<concepts>` header in `<compare>` one.

I tried to quickly resolve those issues including applying suggestions from @cjdb and dive deeper by myself but the problem seems more complicated that we thought initially.

I am in progress to prepare the patch with resolving this cyclic dependency between headers but for now I decided to put all that I have to the review to unblock people that depend on that functionality. At first glance the patch with resolving cyclic dependency is not so small (unless I find the way to make it smaller and cleaner) so I don't want to mix everything to one review.

Reviewed By: ldionne, cjdb, #libc, Quuxplusone

Differential Revision: https://reviews.llvm.org/D103478