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 55698385694E for ; Mon, 7 Aug 2023 21:14:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 55698385694E 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=1691442864; 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=hccDSP+WebWzkrK2UbN4Yk8eguO4T8MXC9za3CnwSMU=; b=BsLwF2dQ/hHybYVz3b2suzLgjmTMTCqdLcV80l7wsHUhVM15OukZ4PlR0qK0N4zk37DwFQ VkSYFICeXl6Gb0Ti2kOcwBRM53b3MfKfLSd4jUyAscjRUDArIyy5sAHT36N4BZP0l8cYVZ 3nDs7ndh2TxOVSSB/h2hkglJgALFiDs= 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-468-2DdmvXU5PJ6spnh9wSZKLQ-1; Mon, 07 Aug 2023 17:14:22 -0400 X-MC-Unique: 2DdmvXU5PJ6spnh9wSZKLQ-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 4D33685C710; Mon, 7 Aug 2023 21:14:22 +0000 (UTC) Received: from localhost (unknown [10.42.28.127]) by smtp.corp.redhat.com (Postfix) with ESMTP id 14535492C13; Mon, 7 Aug 2023 21:14:21 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Constrain __format::_Iter_sink for contiguous iterators [PR110917] Date: Mon, 7 Aug 2023 22:14:01 +0100 Message-ID: <20230807211421.701784-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 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=-11.8 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_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP 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. gcc-13 backport to follow. -- >8 -- We can't write to a span<_CharT> if the contiguous iterator has a value type that isn't _CharT. libstdc++-v3/ChangeLog: PR libstdc++/110917 * include/std/format (__format::_Iter_sink): Constrain partial specialization for contiguous iterators to require the value type to be CharT. * testsuite/std/format/functions/format_to.cc: New test. --- libstdc++-v3/include/std/format | 1 + .../std/format/functions/format_to.cc | 100 ++++++++++++++++++ 2 files changed, 101 insertions(+) create mode 100644 libstdc++-v3/testsuite/std/format/functions/format_to.cc diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 0debbae5ba8..60e53642b11 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -2536,6 +2536,7 @@ namespace __format // not introduce any invalid pointer arithmetic or overflows that would not // have happened anyway. template + requires same_as, _CharT> class _Iter_sink<_CharT, _OutIter> : public _Sink<_CharT> { using uint64_t = __UINTPTR_TYPE__; diff --git a/libstdc++-v3/testsuite/std/format/functions/format_to.cc b/libstdc++-v3/testsuite/std/format/functions/format_to.cc new file mode 100644 index 00000000000..a35568954e2 --- /dev/null +++ b/libstdc++-v3/testsuite/std/format/functions/format_to.cc @@ -0,0 +1,100 @@ +// { dg-options "-std=gnu++20" } +// { dg-do run { target c++20 } } + +#include +#include +#include +#include +#include + +struct punct : std::numpunct +{ + std::string do_grouping() const override { return "\2"; } +}; + +void +test() +{ + char buf[32] = { }; + auto out = std::format_to(buf, "test"); + VERIFY( out == buf+4 ); + + std::locale loc({}, new punct); + auto out2 = std::format_to(buf, loc, "{:Ld}", 12345); + VERIFY( out2 == buf+7 ); + VERIFY( std::string_view(buf, out2 - buf) == "1,23,45" ); +} + +struct wpunct : std::numpunct +{ + std::string do_grouping() const override { return "\2"; } +}; + +void +test_wchar() +{ + wchar_t buf[32] = { }; + auto out = std::format_to(buf, L"123 + 456 = {}", 579); + VERIFY( out == buf+15 ); + + std::locale loc({}, new wpunct); + auto out2 = std::format_to(buf, loc, L"{:Ld}", 12345); + VERIFY( out2 == buf+7 ); + VERIFY( std::wstring_view(buf, out2 - buf) == L"1,23,45" ); +} + +template +struct move_only_iterator +{ + using iterator = I; + using value_type = iterator::value_type; + using difference_type = iterator::difference_type; + using iterator_category = std::output_iterator_tag; + + move_only_iterator(iterator b) : base_(b) { } + move_only_iterator(move_only_iterator&&) = default; + move_only_iterator& operator=(move_only_iterator&&) = default; + + move_only_iterator& operator++() { ++base_; return *this; } + move_only_iterator operator++(int) { auto tmp = *this; ++base_; return tmp; } + + decltype(auto) operator*() { return *base_; } + +private: + iterator base_; +}; + +void +test_move_only() +{ + std::string str; + move_only_iterator mo(std::back_inserter(str)); + auto res = std::format_to(std::move(mo), "for{:.3} that{:c}", + "matte", (int)'!'); + VERIFY( str == "format that!" ); + + std::vector vec; + move_only_iterator wmo(std::back_inserter(vec)); + auto wres = std::format_to(std::move(wmo), L"for{:.3} hat{:c}", + L"matte", (long)L'!'); + VERIFY( std::wstring_view(vec.data(), vec.size()) == L"format hat!" ); +} + +void +test_pr110917() +{ + // PR libstdc++/110917 + // std::format_to(int*, ...) fails to compile because of _S_make_span + unsigned char buf[7]; + auto res = std::format_to(buf, "{} {}", "abc", 123); + VERIFY( res == buf + 7 ); + VERIFY( ! std::memcmp(buf, "abc 123", 7) ); +} + +int main() +{ + test(); + test_wchar(); + test_move_only(); + test_pr110917(); +} -- 2.41.0