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 7CC3338582B7 for ; Tue, 1 Nov 2022 12:34:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7CC3338582B7 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=1667306059; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=npviCbwJTFAqououuR3va38V6cVErzdyLqH+zr9Zgo8=; b=Jt/VQ+njSiO+ThVvhmdLy4moB4wUmEd6U1mKX54J9SnuAzENxwzJcvjZNFUQMFiaChcxh1 OmtMh0GxguKMYtfOC4B7YKqqc9+MdNIp98XVNHEVxPbqgdZg/ubEMQlFWrokiMKDXfCJ5o H4c/doZGVP9Ef7E5Hy14+f0dFL0P7t8= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-459-AQB0gTzpOviFXEdG437Y5A-1; Tue, 01 Nov 2022 08:34:17 -0400 X-MC-Unique: AQB0gTzpOviFXEdG437Y5A-1 Received: by mail-ej1-f69.google.com with SMTP id he6-20020a1709073d8600b0078e20190301so7863728ejc.22 for ; Tue, 01 Nov 2022 05:34:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=npviCbwJTFAqououuR3va38V6cVErzdyLqH+zr9Zgo8=; b=l16DmZGGzesFvx26rOr4nFIzgeZKwPl2jiPLF5JcBBuc8TXmGpYOSkrcQ/g5UnHhQz pMODXRKWLkaGykQWb+7gg3W683pqh7WEXuz6sDMTVaXbytJjU9te5GU5cc4t6l/3s+l7 xb2aen1ib//vAJGMfN9kaPwFZtufsuWY80MkyjDIyDVsl95Y6aG6InWWComOHRQ8AKj6 zbcBaPng2JkzQeHdFZhJfWvI1U2G2QTd1lTjFMB/3XqFtd9yQfOd7lkDgrokmpgMMEJS D1PD2Culc9nTm/LR66edZb5A7xZjP4HnXz2z1V8EqzYN+mv5PxGarnKEaRtaJmxRNhXD qnEA== X-Gm-Message-State: ACrzQf251Pqx/X7EpNRSXc490rpmuxPzOjx6r1dMsD6+Mvi6dejx7U6B W6oaESS2sokxNClEmCJiGraoOTVeMEFKU8pHtdIXFcE4MNbiRR1pP9OzsH81pQJWs6Tz7UJ0QKD pdZGABd4EiJVzScEywr4tGVvXhCNDXdE= X-Received: by 2002:a17:906:cc58:b0:7a9:6b4e:79e4 with SMTP id mm24-20020a170906cc5800b007a96b4e79e4mr17524842ejb.57.1667306056900; Tue, 01 Nov 2022 05:34:16 -0700 (PDT) X-Google-Smtp-Source: AMsMyM7/yf+cmi+enKRioz+tpYh9zP5krSJ31QvKpuoBU/fjRLnS/4OiQlLHMCv3tGAim7NlxVcZ57petQTsyZJKhkk= X-Received: by 2002:a17:906:cc58:b0:7a9:6b4e:79e4 with SMTP id mm24-20020a170906cc5800b007a96b4e79e4mr17524831ejb.57.1667306056719; Tue, 01 Nov 2022 05:34:16 -0700 (PDT) MIME-Version: 1.0 References: <20221031203310.852924-1-ppalka@redhat.com> In-Reply-To: <20221031203310.852924-1-ppalka@redhat.com> From: Jonathan Wakely Date: Tue, 1 Nov 2022 12:34:06 +0000 Message-ID: Subject: Re: [PATCH] libstdc++: Implement ranges::as_rvalue_view from P2446R2 To: Patrick Palka Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-14.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,KAM_NUMSUBJECT,KAM_SHORT,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,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: On Mon, 31 Oct 2022 at 20:33, Patrick Palka via Libstdc++ wrote: > > Tested on x86_64-pc-linux-gnu, does this look OK for trunk? OK, thanks. We should update https://gcc.gnu.org/gcc-13/changes.html#libstdcxx again soon. > > libstdc++-v3/ChangeLog: > > * include/std/ranges (as_rvalue_view): Define. > (enable_borrowed_range): Define. > (views::__detail::__can_as_rvalue_view): Define. > (views::_AsRvalue, views::as_rvalue): Define. > * testsuite/std/ranges/adaptors/as_rvalue/1.cc: New test. > --- > libstdc++-v3/include/std/ranges | 88 +++++++++++++++++++ > .../std/ranges/adaptors/as_rvalue/1.cc | 47 ++++++++++ > 2 files changed, 135 insertions(+) > create mode 100644 libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc > > diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges > index 959886a1a55..239b3b61d30 100644 > --- a/libstdc++-v3/include/std/ranges > +++ b/libstdc++-v3/include/std/ranges > @@ -8486,6 +8486,94 @@ namespace views::__adaptor > > inline constexpr _CartesianProduct cartesian_product; > } > + > + template > + requires view<_Vp> > + class as_rvalue_view : public view_interface> > + { > + _Vp _M_base = _Vp(); > + > + public: > + as_rvalue_view() requires default_initializable<_Vp> = default; > + > + constexpr explicit > + as_rvalue_view(_Vp __base) > + : _M_base(std::move(__base)) > + { } > + > + constexpr _Vp > + base() const& requires copy_constructible<_Vp> { return _M_base; } > + > + constexpr _Vp > + base() && { return std::move(_M_base); } > + > + constexpr auto > + begin() requires (!__detail::__simple_view<_Vp>) > + { return move_iterator(ranges::begin(_M_base)); } > + > + constexpr auto > + begin() const requires range > + { return move_iterator(ranges::begin(_M_base)); } > + > + constexpr auto > + end() requires (!__detail::__simple_view<_Vp>) > + { > + if constexpr (common_range<_Vp>) > + return move_iterator(ranges::end(_M_base)); > + else > + return move_sentinel(ranges::end(_M_base)); > + } > + > + constexpr auto > + end() const requires range > + { > + if constexpr (common_range) > + return move_iterator(ranges::end(_M_base)); > + else > + return move_sentinel(ranges::end(_M_base)); > + } > + > + constexpr auto > + size() requires sized_range<_Vp> > + { return ranges::size(_M_base); } > + > + constexpr auto > + size() const requires sized_range > + { return ranges::size(_M_base); } > + }; > + > + template > + as_rvalue_view(_Range&&) -> as_rvalue_view>; > + > + template > + inline constexpr bool enable_borrowed_range> > + = enable_borrowed_range<_Tp>; > + > + namespace views > + { > + namespace __detail > + { > + template > + concept __can_as_rvalue_view = requires { as_rvalue_view(std::declval<_Tp>()); }; > + } > + > + struct _AsRvalue : __adaptor::_RangeAdaptorClosure > + { > + template > + requires __detail::__can_as_rvalue_view<_Range> > + constexpr auto > + operator() [[nodiscard]] (_Range&& __r) const > + { > + if constexpr (same_as, > + range_reference_t<_Range>>) > + return views::all(std::forward<_Range>(__r)); > + else > + return as_rvalue_view(std::forward<_Range>(__r)); > + } > + }; > + > + inline constexpr _AsRvalue as_rvalue; > + } > #endif // C++23 > } // namespace ranges > > diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc > new file mode 100644 > index 00000000000..8ca4f50e9d2 > --- /dev/null > +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/as_rvalue/1.cc > @@ -0,0 +1,47 @@ > +// { dg-options "-std=gnu++23" } > +// { dg-do run { target c++23 } } > + > +#include > +#include > +#include > +#include > +#include > + > +namespace ranges = std::ranges; > +namespace views = std::views; > + > +constexpr bool > +test01() > +{ > + > + std::unique_ptr a[3] = { std::make_unique(1), > + std::make_unique(2), > + std::make_unique(3) }; > + std::unique_ptr b[3]; > + auto v = a | views::as_rvalue; > + ranges::copy(v, b); > + VERIFY( ranges::all_of(a, [](auto& p) { return p.get() == nullptr; }) ); > + VERIFY( ranges::equal(b | views::transform([](auto& p) { return *p; }), (int[]){1, 2, 3}) ); > + > + return true; > +} > + > +void > +test02() > +{ > + std::unique_ptr x = std::make_unique(42); > + std::unique_ptr y; > + __gnu_test::test_input_range rx(&x, &x+1); > + auto v = rx | views::as_rvalue; > + static_assert(!ranges::common_range); > + ranges::copy(v, &y); > + VERIFY( x.get() == nullptr ); > + VERIFY( *y == 42 ); > +} > + > +int > +main() > +{ > + static_assert(test01()); > + test02(); > +} > -- > 2.38.1.381.gc03801e19c >