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 4D2AA3AA9430 for ; Fri, 18 Jun 2021 14:06:49 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4D2AA3AA9430 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-556-PMjbTXVYNZO-1thjSMVReQ-1; Fri, 18 Jun 2021 10:06:45 -0400 X-MC-Unique: PMjbTXVYNZO-1thjSMVReQ-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 72B0C800C60; Fri, 18 Jun 2021 14:06:44 +0000 (UTC) Received: from localhost (unknown [10.33.36.175]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1F3115DD68; Fri, 18 Jun 2021 14:06:43 +0000 (UTC) Date: Fri, 18 Jun 2021 15:06:43 +0100 From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Replace incorrect static assertion in std::reduce [PR95833] 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="Gf8EqXTyhLOmS/ZT" 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, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=unavailable autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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: Fri, 18 Jun 2021 14:06:50 -0000 --Gf8EqXTyhLOmS/ZT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline The standard does not require the iterator's value type to be convertible to the result type, it only requires that the result of dereferencing the iterator can be passed to the binary function. libstdc++-v3/ChangeLog: PR libstdc++/95833 * include/std/numeric (reduce(Iter, Iter, T, BinaryOp)): Replace incorrect static_assert with ones matching the 'Mandates' conditions in the standard. * testsuite/26_numerics/reduce/95833.cc: New test. Tested powerpc64le-linux. Committed to trunk. Backports will follow. --Gf8EqXTyhLOmS/ZT Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="patch.txt" commit 0532452dcd17910dfd3d2b0df50dfe3ef1194bf7 Author: Jonathan Wakely Date: Fri Jun 18 14:46:58 2021 libstdc++: Replace incorrect static assertion in std::reduce [PR95833] The standard does not require the iterator's value type to be convertible to the result type, it only requires that the result of dereferencing the iterator can be passed to the binary function. libstdc++-v3/ChangeLog: PR libstdc++/95833 * include/std/numeric (reduce(Iter, Iter, T, BinaryOp)): Replace incorrect static_assert with ones matching the 'Mandates' conditions in the standard. * testsuite/26_numerics/reduce/95833.cc: New test. diff --git a/libstdc++-v3/include/std/numeric b/libstdc++-v3/include/std/numeric index f36c1f96b2e..2ab337a0f3a 100644 --- a/libstdc++-v3/include/std/numeric +++ b/libstdc++-v3/include/std/numeric @@ -278,9 +278,11 @@ namespace __detail reduce(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOperation __binary_op) { - using value_type = typename iterator_traits<_InputIterator>::value_type; + using __ref = typename iterator_traits<_InputIterator>::reference; + static_assert(is_invocable_r_v<_Tp, _BinaryOperation&, _Tp&, __ref>); + static_assert(is_invocable_r_v<_Tp, _BinaryOperation&, __ref, _Tp&>); static_assert(is_invocable_r_v<_Tp, _BinaryOperation&, _Tp&, _Tp&>); - static_assert(is_convertible_v); + static_assert(is_invocable_r_v<_Tp, _BinaryOperation&, __ref, __ref>); if constexpr (__is_random_access_iter<_InputIterator>::value) { while ((__last - __first) >= 4) diff --git a/libstdc++-v3/testsuite/26_numerics/reduce/95833.cc b/libstdc++-v3/testsuite/26_numerics/reduce/95833.cc new file mode 100644 index 00000000000..cf4644f53c9 --- /dev/null +++ b/libstdc++-v3/testsuite/26_numerics/reduce/95833.cc @@ -0,0 +1,16 @@ +// { dg-do compile { target c++17 } } +// PR libstdc++/95833 - Incorrect static_assert in std::reduce overload + +#include + +struct A { }; +struct B { }; + +struct binop +{ + template + A operator()(T&&, U&&) const { return A{}; } +}; + +B b; +A a = std::reduce(&b, &b + 1, A{}, binop{}); --Gf8EqXTyhLOmS/ZT--