From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1888) id 8C23D3858421; Tue, 14 Mar 2023 20:46:52 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8C23D3858421 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1678826812; bh=Ww8y84o5EquEWEhmqterXCQIalyC0zH3B4xRJXDggIA=; h=From:To:Subject:Date:From; b=OLzGV1V0a92UI9jB+a9AOGuNd2TCnOntGyiybV9qQL2pGwAKU2HgYTMRTN4ciktBT pqCZ1IfXGA66RHYV7WP6jNnMxOsuDI2fOoZwlECgC3wXt79OHpfa85BRIwAuiHDXqv LqFt86rAEas6oc3fJ4YyWt5OHayKfQ6GowQpEV24= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Patrick Palka To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r13-6672] libstdc++: Implement LWG 3715 changes to view_interface::empty X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/heads/master X-Git-Oldrev: 19c5dfc29d83101e415590e778b99e7c37d9b730 X-Git-Newrev: f2e7dd8b023b8de30af608afd68e0ecefa5c1de6 Message-Id: <20230314204652.8C23D3858421@sourceware.org> Date: Tue, 14 Mar 2023 20:46:52 +0000 (GMT) List-Id: https://gcc.gnu.org/g:f2e7dd8b023b8de30af608afd68e0ecefa5c1de6 commit r13-6672-gf2e7dd8b023b8de30af608afd68e0ecefa5c1de6 Author: Patrick Palka Date: Tue Mar 14 16:44:30 2023 -0400 libstdc++: Implement LWG 3715 changes to view_interface::empty libstdc++-v3/ChangeLog: * include/bits/ranges_util.h (view_interface::empty): Add preferred overloads that use ranges::size when the range is sized as per LWG 3715. * testsuite/std/ranges/adaptors/lwg3715.cc: New test. Diff: --- libstdc++-v3/include/bits/ranges_util.h | 16 +++++++++-- .../testsuite/std/ranges/adaptors/lwg3715.cc | 33 ++++++++++++++++++++++ 2 files changed, 47 insertions(+), 2 deletions(-) diff --git a/libstdc++-v3/include/bits/ranges_util.h b/libstdc++-v3/include/bits/ranges_util.h index e4643e31a20..880a0ce0143 100644 --- a/libstdc++-v3/include/bits/ranges_util.h +++ b/libstdc++-v3/include/bits/ranges_util.h @@ -97,15 +97,27 @@ namespace ranges constexpr bool empty() noexcept(noexcept(_S_empty(_M_derived()))) - requires forward_range<_Derived> + requires forward_range<_Derived> && (!sized_range<_Derived>) { return _S_empty(_M_derived()); } + constexpr bool + empty() + noexcept(noexcept(ranges::size(_M_derived()) == 0)) + requires sized_range<_Derived> + { return ranges::size(_M_derived()) == 0; } + constexpr bool empty() const noexcept(noexcept(_S_empty(_M_derived()))) - requires forward_range + requires forward_range && (!sized_range) { return _S_empty(_M_derived()); } + constexpr bool + empty() const + noexcept(noexcept(ranges::size(_M_derived()) == 0)) + requires sized_range + { return ranges::size(_M_derived()) == 0; } + constexpr explicit operator bool() noexcept(noexcept(ranges::empty(_M_derived()))) requires requires { ranges::empty(_M_derived()); } diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/lwg3715.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/lwg3715.cc new file mode 100644 index 00000000000..96ee7087be0 --- /dev/null +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/lwg3715.cc @@ -0,0 +1,33 @@ +// { dg-options "-std=gnu++23" } +// { dg-do run { target c++23 } } + +// Verify LWG 3715 changes. + +#include +#include +#include + +void +test01() +{ + std::istringstream ints("0 1 2 3 4"); + auto i = std::views::istream(ints); + auto r4 = std::views::counted(i.begin(), 4) | std::views::chunk(2); + VERIFY( !r4.empty() ); +} + +void +test02() +{ + std::istringstream ints("0 1 2 3 4"); + auto i = std::views::istream(ints); + auto r0 = std::views::counted(i.begin(), 0) | std::views::chunk(2); + VERIFY( r0.empty() ); +} + +int +main() +{ + test01(); + test02(); +}