From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id BCDA3385801B; Wed, 24 Nov 2021 11:51:02 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BCDA3385801B 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 r11-9286] libstdc++: Add static assertions for std::function requirements X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/releases/gcc-11 X-Git-Oldrev: e1e44deddfa2424e45507a7a4c19c99638c6b08d X-Git-Newrev: 1caca76928ab46cba0b85a649ff6f22a1c1d05c4 Message-Id: <20211124115102.BCDA3385801B@sourceware.org> Date: Wed, 24 Nov 2021 11:51:02 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Nov 2021 11:51:02 -0000 https://gcc.gnu.org/g:1caca76928ab46cba0b85a649ff6f22a1c1d05c4 commit r11-9286-g1caca76928ab46cba0b85a649ff6f22a1c1d05c4 Author: Jonathan Wakely Date: Thu Aug 26 13:13:27 2021 +0100 libstdc++: Add static assertions for std::function requirements Add static assertions to std::function, so that more user-friendly diagnostics are given when trying to store a non-copyable target object. These preconditions were added as "Mandates:" by LWG 2447, but I'm committing them separately from implementing that, to allow just this change to be backported more easily. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * include/bits/std_function.h (function::function(F)): Add static assertions to check constructibility requirements. (cherry picked from commit 8cf428bfd3ca967b3d135e311d3e391998a39335) Diff: --- libstdc++-v3/include/bits/std_function.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libstdc++-v3/include/bits/std_function.h b/libstdc++-v3/include/bits/std_function.h index fb86ff1c5f8..e081cd81ef4 100644 --- a/libstdc++-v3/include/bits/std_function.h +++ b/libstdc++-v3/include/bits/std_function.h @@ -422,6 +422,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION function(_Functor __f) : _Function_base() { + static_assert(is_copy_constructible<_Functor>::value, + "std::function target must be copy-constructible"); + static_assert(is_constructible<_Functor, _Functor>::value, + "std::function target must be constructible from the " + "constructor argument"); + using _My_handler = _Function_handler<_Res(_ArgTypes...), _Functor>; if (_My_handler::_M_not_empty_function(__f))