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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id A95443858427 for ; Thu, 1 Sep 2022 19:33:44 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org A95443858427 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-665-6JIG3f2OPb6-PIRPpMVpWw-1; Thu, 01 Sep 2022 15:33:41 -0400 X-MC-Unique: 6JIG3f2OPb6-PIRPpMVpWw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id EA0D3185A794; Thu, 1 Sep 2022 19:33:40 +0000 (UTC) Received: from localhost (unknown [10.33.36.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id ACC6F492CA2; Thu, 1 Sep 2022 19:33:40 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Add specializations for some variable templates Date: Thu, 1 Sep 2022 20:33:40 +0100 Message-Id: <20220901193340.352562-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-12.3 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, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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: Thu, 01 Sep 2022 19:33:45 -0000 Tested powerpc64le-linux, pushed to trunk. -- >8 -- This avoids having to instantiate a class template when we can detect the true cases easily with a partial specialization. libstdc++-v3/ChangeLog: * include/std/type_traits (is_lvalue_reference_v) (is_rvalue_reference_v, is_reference_v, is_const_v) (is_volatile_v): Define using partial specializations instead of instantiating class templates. --- libstdc++-v3/include/std/type_traits | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index 52cca8bf3af..e4b9b59ce08 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -3153,11 +3153,13 @@ template template inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; template - inline constexpr bool is_lvalue_reference_v = - is_lvalue_reference<_Tp>::value; + inline constexpr bool is_lvalue_reference_v = false; template - inline constexpr bool is_rvalue_reference_v = - is_rvalue_reference<_Tp>::value; + inline constexpr bool is_lvalue_reference_v<_Tp&> = true; +template + inline constexpr bool is_rvalue_reference_v = false; +template + inline constexpr bool is_rvalue_reference_v<_Tp&&> = true; template inline constexpr bool is_member_object_pointer_v = is_member_object_pointer<_Tp>::value; @@ -3173,7 +3175,11 @@ template template inline constexpr bool is_function_v = is_function<_Tp>::value; template - inline constexpr bool is_reference_v = is_reference<_Tp>::value; + inline constexpr bool is_reference_v = false; +template + inline constexpr bool is_reference_v<_Tp&> = true; +template + inline constexpr bool is_reference_v<_Tp&&> = true; template inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value; template @@ -3187,9 +3193,13 @@ template template inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value; template - inline constexpr bool is_const_v = is_const<_Tp>::value; + inline constexpr bool is_const_v = false; template - inline constexpr bool is_volatile_v = is_volatile<_Tp>::value; + inline constexpr bool is_const_v = true; +template + inline constexpr bool is_volatile_v = false; +template + inline constexpr bool is_volatile_v = true; template inline constexpr bool is_trivial_v = is_trivial<_Tp>::value; template -- 2.37.2