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 7C0FF385800D for ; Tue, 28 Sep 2021 19:25:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7C0FF385800D 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-490-G-iyBkFYMbi1dnC-bzJNdA-1; Tue, 28 Sep 2021 15:25:05 -0400 X-MC-Unique: G-iyBkFYMbi1dnC-bzJNdA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 77E77DF8A0; Tue, 28 Sep 2021 19:25:04 +0000 (UTC) Received: from localhost (unknown [10.33.36.241]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2878F18EDF; Tue, 28 Sep 2021 19:25:03 +0000 (UTC) Date: Tue, 28 Sep 2021 20:25:03 +0100 From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Specialize std::pointer_traits<__normal_iterator> Message-ID: MIME-Version: 1.0 X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/mixed; boundary="PfD/t+WUneGpDriK" Content-Disposition: inline X-Spam-Status: No, score=-13.8 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, 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: Tue, 28 Sep 2021 19:25:08 -0000 --PfD/t+WUneGpDriK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline This allows std::__to_address to be used with __normal_iterator in C++11/14/17 modes. Without the partial specialization the deduced pointer_traits::element_type is incorrect, and so the return type of __to_address is wrong. A similar partial specialization is probably needed for __gnu_debug::_Safe_iterator. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/stl_iterator.h (pointer_traits): Define partial specialization for __normal_iterator. * testsuite/24_iterators/normal_iterator/to_address.cc: New test. Tested x86_64-linux. Committed to trunk. --PfD/t+WUneGpDriK Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="patch.txt" commit 82626be2d633a9802a8b08727ef51c627e37fee5 Author: Jonathan Wakely Date: Tue Sep 28 15:26:46 2021 libstdc++: Specialize std::pointer_traits<__normal_iterator> This allows std::__to_address to be used with __normal_iterator in C++11/14/17 modes. Without the partial specialization the deduced pointer_traits::element_type is incorrect, and so the return type of __to_address is wrong. A similar partial specialization is probably needed for __gnu_debug::_Safe_iterator. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/stl_iterator.h (pointer_traits): Define partial specialization for __normal_iterator. * testsuite/24_iterators/normal_iterator/to_address.cc: New test. diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h index c5b02408c1c..004d767224d 100644 --- a/libstdc++-v3/include/bits/stl_iterator.h +++ b/libstdc++-v3/include/bits/stl_iterator.h @@ -1285,6 +1285,34 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { return __it.base(); } #if __cplusplus >= 201103L + + // Need to specialize pointer_traits because the primary template will + // deduce element_type of __normal_iterator as T* rather than T. + template + struct pointer_traits<__gnu_cxx::__normal_iterator<_Iterator, _Container>> + { + private: + using _Base = pointer_traits<_Iterator>; + + public: + using element_type = typename _Base::element_type; + using pointer = __gnu_cxx::__normal_iterator<_Iterator, _Container>; + using difference_type = typename _Base::difference_type; + + template + using rebind = __gnu_cxx::__normal_iterator<_Tp, _Container>; + + static pointer + pointer_to(element_type& __e) noexcept + { return pointer(_Base::pointer_to(__e)); } + +#if __cplusplus >= 202002L + static element_type* + to_address(pointer __p) noexcept + { return __p.base(); } +#endif + }; + /** * @addtogroup iterators * @{ diff --git a/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc b/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc new file mode 100644 index 00000000000..510d627435f --- /dev/null +++ b/libstdc++-v3/testsuite/24_iterators/normal_iterator/to_address.cc @@ -0,0 +1,6 @@ +// { dg-do compile { target { c++11 } } } +#include +#include + +char* p = std::__to_address(std::string("1").begin()); +const char* q = std::__to_address(std::string("2").cbegin()); --PfD/t+WUneGpDriK--