From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2136) id 0DFB53954424; Wed, 17 Jun 2020 18:26:46 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0DFB53954424 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1592418406; bh=wlwIaqxd3Ce1yMFHYjsrirQQOhLNfowRzw4KJaANFrs=; h=From:To:Subject:Date:From; b=GU3adqH9YocNJ4Y/sez4m+WvCcwj9L45/6tna9GeqrN0GSfgIbld50+8efUe2cnBk pqfigaKk4vrlqNuN7TuGw3X00xjaZS1QG4zvAVR4dAjrFm9y9dD2WgQXMUZTiZnngo yehGr2uGSbWHSIaIgyh1ImEYJHnDMcakYhMIeRbs= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Aldy Hernandez To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc/devel/ranger] libstdc++: Simplify constraints on std::compare_three_way X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/devel/ranger X-Git-Oldrev: 83b0201035cfdc1d4d80153f4e19ec98cf059941 X-Git-Newrev: f214ffb336d582a66149068a2a96b7fcf395b5de Message-Id: <20200617182646.0DFB53954424@sourceware.org> Date: Wed, 17 Jun 2020 18:26:46 +0000 (GMT) X-BeenThere: libstdc++-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Jun 2020 18:26:46 -0000 https://gcc.gnu.org/g:f214ffb336d582a66149068a2a96b7fcf395b5de commit f214ffb336d582a66149068a2a96b7fcf395b5de Author: Jonathan Wakely Date: Wed Jan 29 13:56:49 2020 +0000 libstdc++: Simplify constraints on std::compare_three_way The __3way_builtin_ptr_cmp concept can use three_way_comparable_with to check whether <=> is valid. Doing that makes it obvious that the disjunction on compare_three_way::operator() is redundant, because the second constraint subsumes the first. The workaround for PR c++/91073 can also be removed as that bug is fixed now. * libsupc++/compare (__detail::__3way_builtin_ptr_cmp): Use three_way_comparable_with. (__detail::__3way_cmp_with): Remove workaround for fixed bug. (compare_three_way::operator()): Remove redundant constraint from requires-clause. (__detail::_Synth3way::operator()): Use three_way_comparable_with instead of workaround. * testsuite/18_support/comparisons/object/93479.cc: Prune extra output due to simplified constraints on compare_three_way::operator(). Diff: --- libstdc++-v3/ChangeLog | 10 ++++++++++ libstdc++-v3/libsupc++/compare | 12 +++--------- .../testsuite/18_support/comparisons/object/93479.cc | 2 ++ 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 2c3d33e96ca..e9a8a677e4c 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,15 @@ 2020-01-29 Jonathan Wakely + * libsupc++/compare (__detail::__3way_builtin_ptr_cmp): Use + three_way_comparable_with. + (__detail::__3way_cmp_with): Remove workaround for fixed bug. + (compare_three_way::operator()): Remove redundant constraint from + requires-clause. + (__detail::_Synth3way::operator()): Use three_way_comparable_with + instead of workaround. + * testsuite/18_support/comparisons/object/93479.cc: Prune extra + output due to simplified constraints on compare_three_way::operator(). + PR libstdc++/93479 * libsupc++/compare (__3way_builtin_ptr_cmp): Require <=> to be valid. * testsuite/18_support/comparisons/object/93479.cc: New test. diff --git a/libstdc++-v3/libsupc++/compare b/libstdc++-v3/libsupc++/compare index aabd0c56530..a7a29ef0440 100644 --- a/libstdc++-v3/libsupc++/compare +++ b/libstdc++-v3/libsupc++/compare @@ -525,26 +525,20 @@ namespace std // BUILTIN-PTR-THREE-WAY(T, U) template concept __3way_builtin_ptr_cmp - = requires(_Tp&& __t, _Up&& __u) - { static_cast<_Tp&&>(__t) <=> static_cast<_Up&&>(__u); } + = three_way_comparable_with<_Tp, _Up> && convertible_to<_Tp, const volatile void*> && convertible_to<_Up, const volatile void*> && ! requires(_Tp&& __t, _Up&& __u) { operator<=>(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); } && ! requires(_Tp&& __t, _Up&& __u) { static_cast<_Tp&&>(__t).operator<=>(static_cast<_Up&&>(__u)); }; - - // FIXME: workaround for PR c++/91073 - template - concept __3way_cmp_with = three_way_comparable_with<_Tp, _Up>; } // namespace __detail // [cmp.object], typename compare_three_way struct compare_three_way { template - requires (__detail::__3way_cmp_with<_Tp, _Up> - || __detail::__3way_builtin_ptr_cmp<_Tp, _Up>) + requires three_way_comparable_with<_Tp, _Up> constexpr auto operator()(_Tp&& __t, _Up&& __u) const noexcept { @@ -919,7 +913,7 @@ namespace std { __u < __t } -> convertible_to; } { - if constexpr (__3way_cmp_with<_Tp, _Up>) + if constexpr (three_way_comparable_with<_Tp, _Up>) return __t <=> __u; else { diff --git a/libstdc++-v3/testsuite/18_support/comparisons/object/93479.cc b/libstdc++-v3/testsuite/18_support/comparisons/object/93479.cc index 7da1df15848..f4f0a36685b 100644 --- a/libstdc++-v3/testsuite/18_support/comparisons/object/93479.cc +++ b/libstdc++-v3/testsuite/18_support/comparisons/object/93479.cc @@ -42,3 +42,5 @@ test02() std::compare_three_way{}(x, ""); // { dg-error "no match" } std::compare_three_way{}("", x); // { dg-error "no match" } } + +// { dg-prune-output "in requirements with" }