From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTP id 5E4B53848412 for ; Wed, 11 Aug 2021 16:00:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 5E4B53848412 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-8-M2WIhsvMOsixzhXksSsQ1Q-1; Wed, 11 Aug 2021 12:00:14 -0400 X-MC-Unique: M2WIhsvMOsixzhXksSsQ1Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2266D801AEB; Wed, 11 Aug 2021 16:00:14 +0000 (UTC) Received: from localhost (unknown [10.33.36.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9EDF65D6AD; Wed, 11 Aug 2021 16:00:13 +0000 (UTC) Date: Wed, 11 Aug 2021 17:00:12 +0100 From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Define std::is_pointer_interconvertible_base_of for C++20 Message-ID: MIME-Version: 1.0 X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/mixed; boundary="VlHMJLx9fsVTw/7l" Content-Disposition: inline X-Spam-Status: No, score=-13.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_NUMSUBJECT, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Aug 2021 16:00:27 -0000 --VlHMJLx9fsVTw/7l Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Implement these traits using the new built-ins that Jakub added recently. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/std/type_traits (__cpp_lib_is_pointer_interconvertible) (is_pointer_interconvertible_base_of_v) (is_pointer_interconvertible_base_of): Define for C++20. * include/std/version (__cpp_lib_is_pointer_interconvertible): Define. * testsuite/23_containers/span/layout_compat.cc: Use correct feature test macro for std::is_layout_compatible_v. * testsuite/20_util/is_pointer_interconvertible/value.cc: New test. * testsuite/20_util/is_pointer_interconvertible/version.cc: New test. Tested powerpc64le-linux. Committed to trunk. --VlHMJLx9fsVTw/7l Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="patch.txt" commit 4fa6c0ec350bb4a8dd52a7c6f9881ab427151588 Author: Jonathan Wakely Date: Tue Aug 10 15:37:23 2021 libstdc++: Define std::is_pointer_interconvertible_base_of for C++20 Implement these traits using the new built-ins that Jakub added recently. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/std/type_traits (__cpp_lib_is_pointer_interconvertible) (is_pointer_interconvertible_base_of_v) (is_pointer_interconvertible_base_of): Define for C++20. * include/std/version (__cpp_lib_is_pointer_interconvertible): Define. * testsuite/23_containers/span/layout_compat.cc: Use correct feature test macro for std::is_layout_compatible_v. * testsuite/20_util/is_pointer_interconvertible/value.cc: New test. * testsuite/20_util/is_pointer_interconvertible/version.cc: New test. diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index 46edde905f8..2be4944e2a6 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -3389,6 +3389,33 @@ template inline constexpr bool is_unbounded_array_v = is_unbounded_array<_Tp>::value; +#if __has_builtin(__is_pointer_interconvertible_base_of) + /// True if `_Derived` is standard-layout and has a base class of type `_Base` + /// @since C++20 + template + struct is_pointer_interconvertible_base_of + : bool_constant<__is_pointer_interconvertible_base_of(_Base, _Derived)> + { }; + + /// @ingroup variable_templates + /// @since C++20 + template + constexpr bool is_pointer_interconvertible_base_of_v + = __is_pointer_interconvertible_base_of(_Base, _Derived); + +#if __has_builtin(__builtin_is_pointer_interconvertible_with_class) +#define __cpp_lib_is_pointer_interconvertible 201907L + + /// True if `__mp` points to the first member of a standard-layout type + /// @returns true if `s.*__mp` is pointer-interconvertible with `s` + /// @since C++20 + template + constexpr bool + is_pointer_interconvertible_with_class(_Mem _Tp::*__mp) noexcept + { return __builtin_is_pointer_interconvertible_with_class(__mp); } +#endif +#endif + #if __cplusplus > 202002L #define __cpp_lib_is_scoped_enum 202011L diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version index d5fa38d7786..925f27704c4 100644 --- a/libstdc++-v3/include/std/version +++ b/libstdc++-v3/include/std/version @@ -236,6 +236,10 @@ #ifdef _GLIBCXX_HAS_GTHREADS # define __cpp_lib_jthread 201911L #endif +#if __has_builtin(__is_pointer_interconvertible_base_of) \ + && __has_builtin(__builtin_is_pointer_interconvertible_with_class) +# define __cpp_lib_is_pointer_interconvertible 201907L +#endif #if __cpp_lib_atomic_wait # define __cpp_lib_latch 201907L #endif diff --git a/libstdc++-v3/testsuite/20_util/is_pointer_interconvertible/value.cc b/libstdc++-v3/testsuite/20_util/is_pointer_interconvertible/value.cc new file mode 100644 index 00000000000..471571cac58 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_pointer_interconvertible/value.cc @@ -0,0 +1,51 @@ +// { dg-options "-std=gnu++20" } +// { dg-do compile { target c++20 } } +#include + +#ifndef __cpp_lib_is_pointer_interconvertible +# error "Feature test macro for is_pointer_interconvertible is missing in " +#elif __cpp_lib_is_pointer_interconvertible < 201907L +# error "Feature test macro for is_pointer_interconvertible has wrong value in " +#endif + +static_assert( std::is_pointer_interconvertible_base_of::value + == std::is_pointer_interconvertible_base_of_v ); + +struct B { }; + +static_assert( std::is_pointer_interconvertible_base_of::value + == std::is_pointer_interconvertible_base_of_v ); + +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); + +struct D : B { int i; }; + +static_assert( std::is_pointer_interconvertible_base_of_v ); + +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); + +static_assert( ! std::is_pointer_interconvertible_base_of_v ); + +struct E : D { }; +// E is not standard-layout +static_assert( ! std::is_pointer_interconvertible_base_of_v ); + +struct D1 : B { }; +struct D2 : B { }; +struct D3 : D1, D2 { }; +// B is ambiguously derived +static_assert( ! std::is_pointer_interconvertible_base_of_v ); + +union U; +static_assert( ! std::is_pointer_interconvertible_base_of_v ); +static_assert( ! std::is_pointer_interconvertible_base_of_v ); + +struct I; // incomplete +static_assert( std::is_pointer_interconvertible_base_of_v ); +static_assert( std::is_pointer_interconvertible_base_of_v ); diff --git a/libstdc++-v3/testsuite/20_util/is_pointer_interconvertible/version.cc b/libstdc++-v3/testsuite/20_util/is_pointer_interconvertible/version.cc new file mode 100644 index 00000000000..138c4be9f93 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_pointer_interconvertible/version.cc @@ -0,0 +1,10 @@ +// { dg-options "-std=gnu++20" } +// { dg-do compile { target c++20 } } + +#include + +#ifndef __cpp_lib_is_pointer_interconvertible +# error "Feature test macro for is_pointer_interconvertible is missing in " +#elif __cpp_lib_is_pointer_interconvertible < 201907L +# error "Feature test macro for is_pointer_interconvertible has wrong value in " +#endif diff --git a/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc b/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc index 7959aa76633..04947e93dbc 100644 --- a/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc +++ b/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc @@ -27,7 +27,7 @@ struct iovec { void* iov_base; std::size_t iov_len; }; #endif -#if __cpp_lib_is_pointer_interconvertible +#if __cpp_lib_is_layout_compatible using std::is_layout_compatible_v; #else // A poor substitute for is_layout_compatible_v --VlHMJLx9fsVTw/7l--