P0758R1 Implicit conversion traits

Message ID	20180702220916.GA28625@redhat.com
State	New
Headers	show Return-Path: <gcc-patches-return-480876-incoming=patchwork.ozlabs.org@gcc.gnu.org> DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:subject:message-id:mime-version:content-type; q=dns; s= default; b=XVEXCJz0EM3qozyrvDQACNWFL39/vHdaAfCzNN5ycVSrzvQlXFcwV 8N3rrvvNEj9nPYwUpxPNbUgs1Z5g1kkz4ah/PEa2mhsra/8Xvt4/ktKOZBDlG23S 1pa4cROqvbgRu1HXaU2o3bWgopQOnFsRsoEMYX2/EN7Nxu6WOEcXWk= Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk Sender: gcc-patches-owner@gcc.gnu.org Date: Mon, 2 Jul 2018 23:09:16 +0100 From: Jonathan Wakely <jwakely@redhat.com> To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [PATCH] P0758R1 Implicit conversion traits Message-ID: <20180702220916.GA28625@redhat.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="CE+1k2dSO48ffgeK" Content-Disposition: inline User-Agent: Mutt/1.9.2 (2017-12-15)
Series	P0758R1 Implicit conversion traits \| expand P0758R1 Implicit conversion traits

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index b2d3380f024..accea6df648 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -1341,13 +1341,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION bool = __or_<is_void<_From>, is_function<_To>, is_array<_To>>::value> struct __is_convertible_helper - { typedef typename is_void<_To>::type type; }; + { + typedef typename is_void<_To>::type type; +#if __cplusplus > 201703L + typedef type __is_nothrow_type; +#endif + }; template<typename _From, typename _To> class __is_convertible_helper<_From, _To, false> { - template<typename _To1> - static void __test_aux(_To1); + template<typename _To1> + static void __test_aux(_To1) noexcept; template<typename _From1, typename _To1, typename = decltype(__test_aux<_To1>(std::declval<_From1>()))> @@ -1358,8 +1363,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION static false_type __test(...); +#if __cplusplus > 201703L + template<typename _From1, typename _To1, + bool _NoEx = noexcept(__test_aux<_To1>(std::declval<_From1>()))> + static __bool_constant<_NoEx> + __test_nothrow(int); + + template<typename, typename> + static false_type + __test_nothrow(...); +#endif + public: typedef decltype(__test<_From, _To>(0)) type; + +#if __cplusplus > 201703L + typedef decltype(__test_nothrow<_From, _To>(0)) __is_nothrow_type; +#endif }; @@ -1369,6 +1389,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION : public __is_convertible_helper<_From, _To>::type { }; +#if __cplusplus > 201703L + /// is_nothrow_convertible + template<typename _From, typename _To> + struct is_nothrow_convertible + : public __is_convertible_helper<_From, _To>::__is_nothrow_type + { }; + + /// is_nothrow_convertible_v + template<typename _From, typename _To> + inline constexpr bool is_nothrow_convertible_v + = is_nothrow_convertible<_From, _To>::value; +#endif // C++2a // Const-volatile modifications. diff --git a/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/requirements/explicit_instantiation.cc b/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/requirements/explicit_instantiation.cc new file mode 100644 index 00000000000..68f1adecb38 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/requirements/explicit_instantiation.cc @@ -0,0 +1,29 @@ +// Copyright (C) 2018 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 +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +// NB: This file is for testing type_traits with NO OTHER INCLUDES. + +#include <type_traits> + +namespace std +{ + typedef short test_type; + template struct is_nothrow_convertible<test_type, test_type>; +} diff --git a/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/requirements/typedefs.cc b/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/requirements/typedefs.cc new file mode 100644 index 00000000000..3b5c6d51fe1 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/requirements/typedefs.cc @@ -0,0 +1,33 @@ +// Copyright (C) 2018 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 +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +// NB: This file is for testing type_traits with NO OTHER INCLUDES. + +#include <type_traits> + +void test01() +{ + // Check for required typedefs + typedef std::is_nothrow_convertible<int, int> test_type; + typedef test_type::value_type value_type; + typedef test_type::type type; + typedef test_type::type::value_type type_value_type; + typedef test_type::type::type type_type; +} diff --git a/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/value.cc b/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/value.cc new file mode 100644 index 00000000000..5824be4810d --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_nothrow_convertible/value.cc @@ -0,0 +1,177 @@ +// Copyright (C) 2018 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 +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +#include <type_traits> +#include <testsuite_tr1.h> + +void test01() +{ + using std::is_nothrow_convertible; + using namespace __gnu_test; + + // Positive conversion tests. + static_assert(test_relationship<is_nothrow_convertible, + int, int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int, const int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + volatile int, const int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int, float>(true)); + static_assert(test_relationship<is_nothrow_convertible, + double, float>(true)); + static_assert(test_relationship<is_nothrow_convertible, + float, int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int*, const int*>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int*, void*>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int[4], int*>(true)); + static_assert(test_relationship<is_nothrow_convertible, + float&, int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int, const int&>(true)); + static_assert(test_relationship<is_nothrow_convertible, + const int&, int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + float, const int&>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int(int), int(*)(int)>(true)); + static_assert(test_relationship<is_nothrow_convertible, + int(&)(int), int(*)(int)>(true)); + static_assert(test_relationship<is_nothrow_convertible, + EnumType, int>(true)); + static_assert(test_relationship<is_nothrow_convertible, + ClassType, ClassType>(true)); + static_assert(test_relationship<is_nothrow_convertible, + DerivedType, ClassType>(true)); + static_assert(test_relationship<is_nothrow_convertible, + DerivedType*, ClassType*>(true)); + static_assert(test_relationship<is_nothrow_convertible, + DerivedType&, ClassType&>(true)); + + static_assert(test_relationship<is_nothrow_convertible, + const int, const int&>(true)); + + static_assert(test_relationship<is_nothrow_convertible, + void, void>(true)); + static_assert(test_relationship<is_nothrow_convertible, + const void, void>(true)); + static_assert(test_relationship<is_nothrow_convertible, + void, volatile void>(true)); + static_assert(test_relationship<is_nothrow_convertible, + double&, NoexceptExplicitClass>(true)); + static_assert(test_relationship<is_nothrow_convertible, + NoexceptCopyConsClass, + NoexceptCopyConsClass>(true)); + static_assert(test_relationship<is_nothrow_convertible, + const NoexceptCopyConsClass, + NoexceptCopyConsClass>(true)); + static_assert(test_relationship<is_nothrow_convertible, + const NoexceptCopyConsClass&, + NoexceptCopyConsClass>(true)); + static_assert(test_relationship<is_nothrow_convertible, + NoexceptMoveConsClass, + NoexceptMoveConsClass>(true)); + + static_assert(test_relationship<is_nothrow_convertible, + int(int), int(&)(int)>(true)); + + // Negative conversion tests. + static_assert(test_relationship<is_nothrow_convertible, + const int*, int*>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int*, float*>(false)); + static_assert(test_relationship<is_nothrow_convertible, + const int[4], int*>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int[4], int[4]>(false)); + static_assert(test_relationship<is_nothrow_convertible, + const int&, int&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + float&, int&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + float, volatile int&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int(int), int(int)>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int(int), int(*)(void)>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int(*)(int), int(&)(int)>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int, EnumType>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int, ClassType>(false)); + static_assert(test_relationship<is_nothrow_convertible, + ClassType, DerivedType>(false)); + static_assert(test_relationship<is_nothrow_convertible, + ClassType*, DerivedType*>(false)); + static_assert(test_relationship<is_nothrow_convertible, + ClassType&, DerivedType&>(false)); + + static_assert(test_relationship<is_nothrow_convertible, + void, int>(false)); + static_assert(test_relationship<is_nothrow_convertible, + void, float>(false)); + static_assert(test_relationship<is_nothrow_convertible, + void, int(*)(int)>(false)); + + // C++0x + static_assert(test_relationship<is_nothrow_convertible, + int, void>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int[4], void>(false)); + + static_assert(test_relationship<is_nothrow_convertible, + int, int&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + float, volatile float&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + const volatile int, + const volatile int&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + volatile int, volatile int&>(false)); + static_assert(test_relationship<is_nothrow_convertible, + double&, ExplicitClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + int&, ExplicitClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + void*, ExplicitClass>(false)); + + static_assert(test_relationship<is_nothrow_convertible, + ExceptCopyConsClass, + ExceptCopyConsClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + const ExceptCopyConsClass, + ExceptCopyConsClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + const ExceptCopyConsClass&, + ExceptCopyConsClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + ExceptMoveConsClass, + ExceptMoveConsClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + ExceptMoveConsClass&, + ExceptMoveConsClass>(false)); + static_assert(test_relationship<is_nothrow_convertible, + NoexceptMoveConsClass&, + NoexceptMoveConsClass>(false)); +} diff --git a/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc b/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc index 13bca19c7e0..1380fc55c82 100644 --- a/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc +++ b/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc @@ -47,4 +47,4 @@ void test01() // { dg-error "required from here" "" { target *-*-* } 39 } // { dg-error "required from here" "" { target *-*-* } 41 } -// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1793 } +// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1825 } diff --git a/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc b/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc index 9df01550ea3..cbc5300c182 100644 --- a/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc +++ b/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc @@ -47,5 +47,5 @@ void test01() // { dg-error "required from here" "" { target *-*-* } 39 } // { dg-error "required from here" "" { target *-*-* } 41 } -// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1676 } +// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1708 }

P0758R1 Implicit conversion traits

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