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 ESMTPS id 865073857C40 for ; Mon, 25 Sep 2023 08:54:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 865073857C40 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695632041; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=RIrMT3XLXj9x1ohqKsdXulQ/d8EfLYHw5r5fhptgi44=; b=ZuP6xWS0xUCe65H6vXFq8INMgGd85IMywcNuDQOJ27Fwc8ziYXCv11Zgw9PQ/X8LjEVVTI E5OyjA1g+V2iFXRVjFzav+5Oav9Q3KS5UhAy22otepqQXTtkyEpGEz6AsLjFRo685yWVgu sP2Ph6H3EjiJijhxv1jItiQc7odXbvE= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-538-Gmt0O6GXOPKSiorXHvFAzA-1; Mon, 25 Sep 2023 04:53:59 -0400 X-MC-Unique: Gmt0O6GXOPKSiorXHvFAzA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 15B791C294B2; Mon, 25 Sep 2023 08:53:59 +0000 (UTC) Received: from localhost (unknown [10.42.28.103]) by smtp.corp.redhat.com (Postfix) with ESMTP id BEB182026D76; Mon, 25 Sep 2023 08:53:58 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Define C++23 std::forward_like (P2445R1) Date: Mon, 25 Sep 2023 09:53:24 +0100 Message-ID: <20230925085358.2744013-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-9.8 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_NONE,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,RCVD_IN_SBL_CSS,SPF_HELO_NONE,SPF_NONE,TXREP,URIBL_BLACK autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Tested x86_64-linux. Pushed to trunk. -- >8 -- libstdc++-v3/ChangeLog: * include/bits/move.h (forward_list): Define for C++23. * include/bits/version.def (forward_like): Define. * include/bits/version.h: Regenerate. * include/std/utility (__glibcxx_want_forward_like): Define. * testsuite/20_util/forward_like/1.cc: New test. * testsuite/20_util/forward_like/2_neg.cc: New test. * testsuite/20_util/forward_like/version.cc: New test. --- libstdc++-v3/include/bits/move.h | 26 ++++++++ libstdc++-v3/include/bits/version.def | 8 +++ libstdc++-v3/include/bits/version.h | 27 ++++++--- libstdc++-v3/include/std/utility | 5 +- .../testsuite/20_util/forward_like/1.cc | 59 +++++++++++++++++++ .../testsuite/20_util/forward_like/2_neg.cc | 10 ++++ .../testsuite/20_util/forward_like/version.cc | 10 ++++ 7 files changed, 135 insertions(+), 10 deletions(-) create mode 100644 libstdc++-v3/testsuite/20_util/forward_like/1.cc create mode 100644 libstdc++-v3/testsuite/20_util/forward_like/2_neg.cc create mode 100644 libstdc++-v3/testsuite/20_util/forward_like/version.cc diff --git a/libstdc++-v3/include/bits/move.h b/libstdc++-v3/include/bits/move.h index 00997d6f1fb..0151d78aff9 100644 --- a/libstdc++-v3/include/bits/move.h +++ b/libstdc++-v3/include/bits/move.h @@ -89,6 +89,32 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return static_cast<_Tp&&>(__t); } +#if __glibcxx_forward_like // C++ >= 23 + template + [[nodiscard]] + constexpr decltype(auto) + forward_like(_Up&& __x) noexcept + { + constexpr bool __as_rval = is_rvalue_reference_v<_Tp&&>; + + if constexpr (is_const_v>) + { + using _Up2 = remove_reference_t<_Up>; + if constexpr (__as_rval) + return static_cast(__x); + else + return static_cast(__x); + } + else + { + if constexpr (__as_rval) + return static_cast&&>(__x); + else + return static_cast<_Up&>(__x); + } + } +#endif + /** * @brief Convert a value to an rvalue. * @param __t A thing of arbitrary type. diff --git a/libstdc++-v3/include/bits/version.def b/libstdc++-v3/include/bits/version.def index 6252f5478e0..8f008f9048f 100644 --- a/libstdc++-v3/include/bits/version.def +++ b/libstdc++-v3/include/bits/version.def @@ -1542,6 +1542,14 @@ ftms = { }; }; +ftms = { + name = forward_like; + values = { + v = 202207; + cxxmin = 23; + }; +}; + ftms = { name = ios_noreplace; values = { diff --git a/libstdc++-v3/include/std/utility b/libstdc++-v3/include/std/utility index f30e802a88d..bdaf5d4c31b 100644 --- a/libstdc++-v3/include/std/utility +++ b/libstdc++-v3/include/std/utility @@ -68,9 +68,10 @@ #include #include -#define __glibcxx_want_exchange_function -#define __glibcxx_want_constexpr_algorithms #define __glibcxx_want_as_const +#define __glibcxx_want_constexpr_algorithms +#define __glibcxx_want_exchange_function +#define __glibcxx_want_forward_like #define __glibcxx_want_integer_comparison_functions #define __glibcxx_want_to_underlying #define __glibcxx_want_unreachable diff --git a/libstdc++-v3/testsuite/20_util/forward_like/1.cc b/libstdc++-v3/testsuite/20_util/forward_like/1.cc new file mode 100644 index 00000000000..928e60094a3 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/forward_like/1.cc @@ -0,0 +1,59 @@ +// { dg-do compile { target c++23 } } +// { dg-add-options no_pch } + +#include + +#ifndef __cpp_lib_forward_like +# error "Feature-test macro for forward_like missing in " +#elif __cpp_lib_forward_like != 202207L +# error "Feature-test macro for forward_like has wrong value in " +#endif + +template +using forward_like_t = decltype(std::forward_like(std::declval())); + +#if 0 +using std::is_same_v; +#else +#include +template concept is_same_v = std::same_as; +#endif + +static_assert( is_same_v, long&&> ); +static_assert( is_same_v, long&> ); +static_assert( is_same_v, long&&> ); + +static_assert( is_same_v, const long&&> ); +static_assert( is_same_v, const long&> ); +static_assert( is_same_v, const long&&> ); + +static_assert( is_same_v, const long&&> ); +static_assert( is_same_v, const long&> ); +static_assert( is_same_v, const long&&> ); + +static_assert( is_same_v, const long&&> ); +static_assert( is_same_v, const long&> ); +static_assert( is_same_v, const long&&> ); + +static_assert( is_same_v, const long&&> ); +static_assert( is_same_v, const long&> ); +static_assert( is_same_v, const long&&> ); + +static_assert( is_same_v, const long&&> ); +static_assert( is_same_v, const long&> ); +static_assert( is_same_v, const long&&> ); + +static_assert( is_same_v, const long&&> ); +static_assert( is_same_v, const long&> ); +static_assert( is_same_v, const long&&> ); + +static_assert( is_same_v, long&&> ); +static_assert( is_same_v, long&> ); +static_assert( is_same_v, long&&> ); + +static_assert( is_same_v, + const volatile long&&> ); +static_assert( is_same_v, + const volatile long&> ); +static_assert( is_same_v, + const volatile long&&> ); diff --git a/libstdc++-v3/testsuite/20_util/forward_like/2_neg.cc b/libstdc++-v3/testsuite/20_util/forward_like/2_neg.cc new file mode 100644 index 00000000000..ff835af1915 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/forward_like/2_neg.cc @@ -0,0 +1,10 @@ +// { dg-do compile { target c++23 } } + +#include + +auto x1 = std::forward_like(1); // { dg-error "here" } +// { dg-error "forming reference to void" "" { target *-*-* } 0 } +auto x2 = std::forward_like(1); // { dg-error "here" } +// { dg-error "forming reference to qualified function" "" { target *-*-* } 0 } + +// { dg-prune-output "inconsistent deduction for auto return type" } // PR111484 diff --git a/libstdc++-v3/testsuite/20_util/forward_like/version.cc b/libstdc++-v3/testsuite/20_util/forward_like/version.cc new file mode 100644 index 00000000000..058dccfabe2 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/forward_like/version.cc @@ -0,0 +1,10 @@ +// { dg-do preprocess { target c++23 } } +// { dg-add-options no_pch } + +#include + +#ifndef __cpp_lib_forward_like +# error "Feature-test macro for forward_like missing in " +#elif __cpp_lib_forward_like != 202207L +# error "Feature-test macro for forward_like has wrong value in " +#endif -- 2.41.0