From eb8e6a30a442c4c12dc903d6e1817b223bbed4a3 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Thu, 27 Feb 2020 10:52:28 +0000 Subject: [PATCH] libstdc++: Make _GLIBCXX_CONCEPT_CHECKS more constexpr-friendly Although most of the old-style "concept checks" are only really usable with C++98 because they enforce the wrong things, this is a simple change that makes them a bit more useful for C++14 and up. * include/bits/boost_concept_check.h (__function_requires): Add _GLIBCXX14_CONSTEXPR. * testsuite/25_algorithms/min/concept_checks.cc: New test. --- libstdc++-v3/ChangeLog | 6 +++++ .../include/bits/boost_concept_check.h | 2 +- .../25_algorithms/min/concept_checks.cc | 23 +++++++++++++++++++ 3 files changed, 30 insertions(+), 1 deletion(-) create mode 100644 libstdc++-v3/testsuite/25_algorithms/min/concept_checks.cc diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 49f2b59e3ae..0df7126f7c9 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,9 @@ +2020-02-27 Jonathan Wakely + + * include/bits/boost_concept_check.h (__function_requires): Add + _GLIBCXX14_CONSTEXPR. + * testsuite/25_algorithms/min/concept_checks.cc: New test. + 2020-02-26 Patrick Palka PR libstdc++/93936 diff --git a/libstdc++-v3/include/bits/boost_concept_check.h b/libstdc++-v3/include/bits/boost_concept_check.h index a555b3be568..f12c1bdc213 100644 --- a/libstdc++-v3/include/bits/boost_concept_check.h +++ b/libstdc++-v3/include/bits/boost_concept_check.h @@ -57,7 +57,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // as possible at runtime, use as few resources as possible, and hopefully // be elided out of existence... hmmm. template -inline void __function_requires() +_GLIBCXX14_CONSTEXPR inline void __function_requires() { void (_Concept::*__x)() _IsUnused = &_Concept::__constraints; } diff --git a/libstdc++-v3/testsuite/25_algorithms/min/concept_checks.cc b/libstdc++-v3/testsuite/25_algorithms/min/concept_checks.cc new file mode 100644 index 00000000000..ba61ceff340 --- /dev/null +++ b/libstdc++-v3/testsuite/25_algorithms/min/concept_checks.cc @@ -0,0 +1,23 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do compile { target c++14 } } + +#define _GLIBCXX_CONCEPT_CHECKS 1 +#include + +constexpr int i = std::min(1, 2); -- 2.30.2