{"id":2225723,"url":"http://patchwork.ozlabs.org/api/patches/2225723/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/20260421140754.787622-1-tkaminsk@redhat.com/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260421140754.787622-1-tkaminsk@redhat.com>","list_archive_url":null,"date":"2026-04-21T14:02:33","name":"libstdc++: Implement __integral_constant_like in terms of __constexpr_wrapper_like.","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"1052f64db776951c8170b183c8cdfe82a1b92ae2","submitter":{"id":90409,"url":"http://patchwork.ozlabs.org/api/people/90409/?format=json","name":"Tomasz Kamiński","email":"tkaminsk@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/20260421140754.787622-1-tkaminsk@redhat.com/mbox/","series":[{"id":500811,"url":"http://patchwork.ozlabs.org/api/series/500811/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=500811","date":"2026-04-21T14:02:33","name":"libstdc++: Implement __integral_constant_like in terms of __constexpr_wrapper_like.","version":1,"mbox":"http://patchwork.ozlabs.org/series/500811/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2225723/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2225723/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=C1xBlhSM;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=38.145.34.32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org;\n\tdkim=pass (1024-bit key,\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=C1xBlhSM","sourceware.org; dmarc=pass (p=quarantine dis=none)\n header.from=redhat.com","sourceware.org; spf=pass smtp.mailfrom=redhat.com","server2.sourceware.org;\n arc=none smtp.remote-ip=170.10.133.124"],"Received":["from vm01.sourceware.org (vm01.sourceware.org [38.145.34.32])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g0PNM5x3gz1yGs\n\tfor ; Wed, 22 Apr 2026 00:08:51 +1000 (AEST)","from vm01.sourceware.org (localhost [127.0.0.1])\n\tby sourceware.org (Postfix) with ESMTP id 8577A4B9DB43\n\tfor ; Tue, 21 Apr 2026 14:08:49 +0000 (GMT)","from us-smtp-delivery-124.mimecast.com\n (us-smtp-delivery-124.mimecast.com [170.10.133.124])\n by sourceware.org (Postfix) with ESMTP id 3CF414B9DB65\n for ; Tue, 21 Apr 2026 14:07:59 +0000 (GMT)","from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com\n (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by\n relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n cipher=TLS_AES_256_GCM_SHA384) id us-mta-572-UTpFCxX8M3uBwbznOPYb8w-1; Tue,\n 21 Apr 2026 10:07:57 -0400","from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com\n (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest\n SHA256)\n (No client certificate requested)\n by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS\n id 69AB419560B4; Tue, 21 Apr 2026 14:07:56 +0000 (UTC)","from localhost (unknown [10.44.32.186])\n by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP\n id CCD21180047F; Tue, 21 Apr 2026 14:07:55 +0000 (UTC)"],"DKIM-Filter":["OpenDKIM Filter v2.11.0 sourceware.org 8577A4B9DB43","OpenDKIM Filter v2.11.0 sourceware.org 3CF414B9DB65"],"DMARC-Filter":"OpenDMARC Filter v1.4.2 sourceware.org 3CF414B9DB65","ARC-Filter":"OpenARC Filter v1.0.0 sourceware.org 3CF414B9DB65","ARC-Seal":"i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1776780479; cv=none;\n b=sULEn1SIi4q66fUSS+PknNI/jPHmB/KCeHJE+dCNU/sCwdD57STUuXK2kiOqMUuU8gExX+Tja609CD5FENiH+oZSJByykERsWSUJJGfMuCK74nVZOAiUpHt/Tv8Afsd3wTga59HQJKWmnseEuS1kw0bAzb1l7NzuSKVFrLRk8Xg=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1776780479; c=relaxed/simple;\n bh=YxLeY6SnJ5l6oSypWQBagd79K9RGTvXLmsq7rL/r6QE=;\n h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version;\n b=JTFWrbdMRb17PXOLUYZYp5udCrbZCnR1dxr3xasOuQGRUXldI1CEmHjsI/9kiVyNa8kgXFyzYvl2duP/DUpQPHPDmbiiSCENGynKxn9KIXH3UPS00rfFw8ng2Jl5tmoWBF1MEOZOiYTENOpoeoUpvtJtZ5dtQUuxf/itAXighYc=","ARC-Authentication-Results":"i=1; server2.sourceware.org","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1776780478;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:mime-version:mime-version:content-type:content-type:\n content-transfer-encoding:content-transfer-encoding;\n bh=aVVbnhwyZ/nhalRROUoM01iCKC3/YSA4Evr0M99YAXk=;\n b=C1xBlhSMHky22+EFRf9Q8aCHBUs0/9NRLPqhjvasieEa4FzqZnFXvgEyOgON7sL9MH72L/\n 5+hKdyQ7hBHceez5v6HpT8A4AzbQQTTxeaZIRHMGB77POFkUBFpy5yaVm+HxnhhPMUEO5E\n p3d/iQ7Vu3OTjoJa14EANOGZx0B1tAM=","X-MC-Unique":"UTpFCxX8M3uBwbznOPYb8w-1","X-Mimecast-MFC-AGG-ID":"UTpFCxX8M3uBwbznOPYb8w_1776780476","From":"=?utf-8?q?Tomasz_Kami=C5=84ski?= ","To":"libstdc++@gcc.gnu.org,\n\tgcc-patches@gcc.gnu.org","Subject":"[PATCH] libstdc++: Implement __integral_constant_like in terms of\n __constexpr_wrapper_like.","Date":"Tue, 21 Apr 2026 16:02:33 +0200","Message-ID":"<20260421140754.787622-1-tkaminsk@redhat.com>","MIME-Version":"1.0","X-Scanned-By":"MIMEDefang 3.4.1 on 10.30.177.93","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"qno4UI_ENX3H4AYsFdhVM7I8hWuCCU6cwOVrXA_4vjA_1776780476","X-Mimecast-Originator":"redhat.com","Content-Transfer-Encoding":"8bit","content-type":"text/plain; charset=\"US-ASCII\"; x-default=true","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"},"content":"This implements LWG4486. integral-constant-like and constexpr-wrapper-like\nexposition-only concept duplication.\n\nlibstdc++-v3/ChangeLog:\n\n\t* include/bits/simd_details.h (simd::__constexpr_wrapper_like):\n\tMove to...\n\t* include/std/concepts (std::__constexpr_wrapper_like): Moved\n\tfrom bits/simd_details.h.\n\t* include/std/span (std::__integral_constant_like): Define in\n\tterms of __constexpr_wrapper_like.\n\t* testsuite/std/simd/traits_impl.cc: Added using declaration\n\tfor std::__constexpr_wrapper_like.\n---\n\nTested on x86_64-linux locally. OK for trunk/stage-1?\nI done it, to double check if they are in sync. This impacts span in C++20 mode,\nso maybe it is safer to keep it for stage-1. From other seems safe, i.e. should\nwork as soon as test passes.\n\n libstdc++-v3/include/bits/simd_details.h | 7 -------\n libstdc++-v3/include/std/concepts | 9 +++++++++\n libstdc++-v3/include/std/span | 8 +++-----\n libstdc++-v3/testsuite/std/simd/traits_impl.cc | 1 +\n 4 files changed, 13 insertions(+), 12 deletions(-)","diff":"diff --git a/libstdc++-v3/include/bits/simd_details.h b/libstdc++-v3/include/bits/simd_details.h\nindex 31bd6ac45ab..408a344d2ec 100644\n--- a/libstdc++-v3/include/bits/simd_details.h\n+++ b/libstdc++-v3/include/bits/simd_details.h\n@@ -1030,13 +1030,6 @@ namespace simd\n /** @internal\n * C++26 [simd.expos]\n */\n- template\n- concept __constexpr_wrapper_like\n- = convertible_to<_Tp, decltype(_Tp::value)>\n-\t && equality_comparable_with<_Tp, decltype(_Tp::value)>\n-\t && bool_constant<_Tp() == _Tp::value>::value\n-\t && bool_constant(_Tp()) == _Tp::value>::value;\n-\n // [simd.ctor] explicit(...) of broadcast ctor\n template \n concept __non_narrowing_constexpr_conversion\ndiff --git a/libstdc++-v3/include/std/concepts b/libstdc++-v3/include/std/concepts\nindex 7673443f33a..328096a89e3 100644\n--- a/libstdc++-v3/include/std/concepts\n+++ b/libstdc++-v3/include/std/concepts\n@@ -421,6 +421,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n \t && ! requires(_Tp&& __t, _Up&& __u)\n \t { static_cast<_Up&&>(__u).operator<=>(static_cast<_Tp&&>(__t)); }));\n }\n+\n+ // [expos.only.entity]\n+ template\n+ concept __constexpr_wrapper_like\n+ = convertible_to<_Tp, decltype(_Tp::value)>\n+\t&& equality_comparable_with<_Tp, decltype(_Tp::value)>\n+\t&& bool_constant<_Tp() == _Tp::value>::value\n+\t&& bool_constant(_Tp()) == _Tp::value>::value;\n+\n _GLIBCXX_END_NAMESPACE_VERSION\n } // namespace\n #endif // __cpp_lib_concepts\ndiff --git a/libstdc++-v3/include/std/span b/libstdc++-v3/include/std/span\nindex a5f5bf48f90..1215ce826f6 100644\n--- a/libstdc++-v3/include/std/span\n+++ b/libstdc++-v3/include/std/span\n@@ -467,15 +467,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION\n {\n // _GLIBCXX_RESOLVE_LIB_DEFECTS\n // 4351. integral-constant-like needs more remove_cvref_t\n+ // 4486. integral-constant-like and constexpr-wrapper-like exposition-only\n+ // concept duplicatiob\n template\n concept __integral_constant_like =\n \tis_integral_v>\n \t&& !is_same_v>\n-\t&& convertible_to<_Tp, decltype(_Tp::value)>\n-\t&& equality_comparable_with<_Tp, decltype(_Tp::value)>\n-\t&& bool_constant<_Tp() == _Tp::value>::value\n-\t&& bool_constant(_Tp()) == _Tp::value>\n-\t ::value;\n+\t&& __constexpr_wrapper_like<_Tp>;\n \n template\n constexpr size_t __maybe_static_ext = dynamic_extent;\ndiff --git a/libstdc++-v3/testsuite/std/simd/traits_impl.cc b/libstdc++-v3/testsuite/std/simd/traits_impl.cc\nindex f73a9e3beb5..2f705c7df2f 100644\n--- a/libstdc++-v3/testsuite/std/simd/traits_impl.cc\n+++ b/libstdc++-v3/testsuite/std/simd/traits_impl.cc\n@@ -16,6 +16,7 @@ using std::float32_t;\n using std::float64_t;\n \n using namespace std::simd;\n+using std::__constexpr_wrapper_like;\n \n template \n void test()\n","prefixes":[]}