From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id 35DDA385781B; Mon, 14 Jun 2021 22:14:11 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 35DDA385781B MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jonathan Wakely To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r12-1440] libstdc++: Fix noexcept-specifier for ranges::empty X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/master X-Git-Oldrev: 20073534c0ccca0a4e079c053ee0874af10b2ea0 X-Git-Newrev: f9598d89a9f5a327ecdfa6f6978a0cfbe4447111 Message-Id: <20210614221411.35DDA385781B@sourceware.org> Date: Mon, 14 Jun 2021 22:14:11 +0000 (GMT) X-BeenThere: libstdc++-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Jun 2021 22:14:11 -0000 https://gcc.gnu.org/g:f9598d89a9f5a327ecdfa6f6978a0cfbe4447111 commit r12-1440-gf9598d89a9f5a327ecdfa6f6978a0cfbe4447111 Author: Jonathan Wakely Date: Mon Jun 14 22:42:05 2021 +0100 libstdc++: Fix noexcept-specifier for ranges::empty Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/ranges_base.h (ranges::empty): Check whether conversion to bool can throw. * testsuite/std/ranges/access/empty.cc: Check for correct noexcept-specifier. Diff: --- libstdc++-v3/include/bits/ranges_base.h | 2 +- libstdc++-v3/testsuite/std/ranges/access/empty.cc | 31 +++++++++++++++++++++++ 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/libstdc++-v3/include/bits/ranges_base.h b/libstdc++-v3/include/bits/ranges_base.h index 728d3ad2b25..3bc657ca17e 100644 --- a/libstdc++-v3/include/bits/ranges_base.h +++ b/libstdc++-v3/include/bits/ranges_base.h @@ -476,7 +476,7 @@ namespace ranges _S_noexcept() { if constexpr (__member_empty<_Tp>) - return noexcept(std::declval<_Tp&>().empty()); + return noexcept(bool(std::declval<_Tp&>().empty())); else if constexpr (__size0_empty<_Tp>) return noexcept(_Size{}(std::declval<_Tp&>()) == 0); else diff --git a/libstdc++-v3/testsuite/std/ranges/access/empty.cc b/libstdc++-v3/testsuite/std/ranges/access/empty.cc index 9044dd155da..b2d8b105325 100644 --- a/libstdc++-v3/testsuite/std/ranges/access/empty.cc +++ b/libstdc++-v3/testsuite/std/ranges/access/empty.cc @@ -89,10 +89,41 @@ test03() static_assert( std::ranges::empty(R2{}) ); } +void +test04() +{ + struct E1 + { + bool empty() const noexcept { return {}; } + }; + + static_assert( noexcept(std::ranges::empty(E1{})) ); + + struct E2 + { + bool empty() const noexcept(false) { return {}; } + }; + + static_assert( ! noexcept(std::ranges::empty(E2{})) ); + + struct E3 + { + struct B + { + explicit operator bool() const noexcept(false) { return true; } + }; + + B empty() const noexcept { return {}; } + }; + + static_assert( ! noexcept(std::ranges::empty(E3{})) ); +} + int main() { test01(); test02(); test03(); + test04(); }