From patchwork Wed Mar 29 23:38:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Wakely X-Patchwork-Id: 67104 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 4F6DB38708D1 for ; Wed, 29 Mar 2023 23:39:37 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4F6DB38708D1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1680133177; bh=t02oKTMHVeOz48ILAqXHKzjsfQDy+SgZB+0ySrFZJng=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=u2J/7SY2C9E8H8tbjzwVqwB8UlScbE+WWsSzezPzpbQQ6XXBo5TQ4ehkhFXCTkciD ZcNTbMYmeDaAOP3rXM9ho5FpOSSRVw7ivV45JHG7mCPdudWk88eEzOGYnsvWjM3nXY lRHUwRu9uaRK0Y0kWgtCBADEKy/byuQebf7PZmd0= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org 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 5E9023857C55 for ; Wed, 29 Mar 2023 23:39:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 5E9023857C55 Received: from mimecast-mx02.redhat.com (mx3-rdu2.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-453-3by4QPqPN9uhM_btNx6P6A-1; Wed, 29 Mar 2023 19:38:59 -0400 X-MC-Unique: 3by4QPqPN9uhM_btNx6P6A-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7D458281424A; Wed, 29 Mar 2023 23:38:59 +0000 (UTC) Received: from localhost (unknown [10.33.36.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4622718EC2; Wed, 29 Mar 2023 23:38:59 +0000 (UTC) To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Enforce requirements on template argument of std::optional Date: Thu, 30 Mar 2023 00:38:58 +0100 Message-Id: <20230329233858.1405145-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.1 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_H2, SPF_HELO_NONE, SPF_NONE, TXREP 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: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Jonathan Wakely via Gcc-patches From: Jonathan Wakely Reply-To: Jonathan Wakely Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Tested powerpc64le-linux. Pushed to trunk. -- >8 -- The standard does not allow std::optional, std::optional, std::optional etc. and although we do give errors, they come from down inside the internals of std::optional. We could improve the static assertions at the top of the class so that users get a more precise diagnostic: optional:721:21: error: static assertion failed 721 | static_assert(is_object_v<_Tp> && !is_array_v<_Tp>); libstdc++-v3/ChangeLog: * include/std/optional (optional): Adjust static assertion to reject arrays and functions as well as references. * testsuite/20_util/optional/requirements_neg.cc: New test. --- libstdc++-v3/include/std/optional | 2 +- .../20_util/optional/requirements_neg.cc | 24 +++++++++++++++++++ 2 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 libstdc++-v3/testsuite/20_util/optional/requirements_neg.cc diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional index 62ff87a3387..90bf74143f4 100644 --- a/libstdc++-v3/include/std/optional +++ b/libstdc++-v3/include/std/optional @@ -718,7 +718,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { static_assert(!is_same_v, nullopt_t>); static_assert(!is_same_v, in_place_t>); - static_assert(!is_reference_v<_Tp>); + static_assert(is_object_v<_Tp> && !is_array_v<_Tp>); private: using _Base = _Optional_base<_Tp>; diff --git a/libstdc++-v3/testsuite/20_util/optional/requirements_neg.cc b/libstdc++-v3/testsuite/20_util/optional/requirements_neg.cc new file mode 100644 index 00000000000..688c305803e --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/optional/requirements_neg.cc @@ -0,0 +1,24 @@ +// { dg-do compile { target c++17 } } + +#include + +// T shall be a type other than cv in_place_t or cv nullopt_t +// that meets the Cpp17Destructible requirements + +std::optional o1; // { dg-error "here" } +std::optional o2; // { dg-error "here" } +std::optional o3; // { dg-error "here" } +std::optional o4; // { dg-error "here" } +std::optional o5; // { dg-error "here" } +std::optional o6; // { dg-error "here" } +std::optional o7; // { dg-error "here" } +std::optional o8; // { dg-error "here" } + +// { dg-error "static assertion failed" "" { target *-*-* } 0 } + +// { dg-prune-output "forming pointer to reference type" } +// { dg-prune-output "union may not have reference type" } +// { dg-prune-output "function returning an array" } +// { dg-prune-output "flexible array member .* in union" } +// { dg-prune-output "function returning a function" } +// { dg-prune-output "invalidly declared function type" }