From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id B8E7F3953CE9; Thu, 8 Apr 2021 16:50:09 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B8E7F3953CE9 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 r11-8062] libstdc++: Simplify noexcept-specifiers for move constructors X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/master X-Git-Oldrev: 59d09f9fe4bcf4a341494220be377dfe13d84c1e X-Git-Newrev: 1cbba49e3417d9b0661e70301d6fb7a7f52fd360 Message-Id: <20210408165009.B8E7F3953CE9@sourceware.org> Date: Thu, 8 Apr 2021 16:50:09 +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: Thu, 08 Apr 2021 16:50:09 -0000 https://gcc.gnu.org/g:1cbba49e3417d9b0661e70301d6fb7a7f52fd360 commit r11-8062-g1cbba49e3417d9b0661e70301d6fb7a7f52fd360 Author: Jonathan Wakely Date: Thu Apr 8 16:29:11 2021 +0100 libstdc++: Simplify noexcept-specifiers for move constructors This puts the logic for the noexcept-specifier in one place, and then reuses it elsewhere. This means checking whether the move constructor can throw doesn't need to do overload resolution and then check whether some other constructor can throw, we just get the answer directly. libstdc++-v3/ChangeLog: * include/bits/hashtable.h (_Hashtable::_S_nothrow_move()): New function to determine noexcept-specifier for move constructors. (_Hashtable): Use _S_nothrow_move() on move constructors. * testsuite/23_containers/unordered_map/cons/noexcept_move_construct.cc: Correct static assertion message. * testsuite/23_containers/unordered_multimap/cons/noexcept_move_construct.cc: Likewise. * testsuite/23_containers/unordered_multiset/cons/noexcept_move_construct.cc: Likewise. * testsuite/23_containers/unordered_set/cons/noexcept_move_construct.cc: Likewise. Diff: --- libstdc++-v3/include/bits/hashtable.h | 26 ++++++++++++---------- .../unordered_map/cons/noexcept_move_construct.cc | 4 ++-- .../cons/noexcept_move_construct.cc | 4 ++-- .../cons/noexcept_move_construct.cc | 4 ++-- .../unordered_set/cons/noexcept_move_construct.cc | 4 ++-- 5 files changed, 22 insertions(+), 20 deletions(-) diff --git a/libstdc++-v3/include/bits/hashtable.h b/libstdc++-v3/include/bits/hashtable.h index fa80675ad91..39872ce5342 100644 --- a/libstdc++-v3/include/bits/hashtable.h +++ b/libstdc++-v3/include/bits/hashtable.h @@ -472,10 +472,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __hashtable_alloc(__node_alloc_type(__a)) { } + template + static constexpr bool + _S_nothrow_move() + { + if _GLIBCXX17_CONSTEXPR (_No_realloc) + if _GLIBCXX17_CONSTEXPR (is_nothrow_copy_constructible<_Hash>()) + return is_nothrow_copy_constructible<_Equal>(); + return false; + } + _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a, true_type /* alloc always equal */) - noexcept(std::is_nothrow_copy_constructible<_Hash>::value && - std::is_nothrow_copy_constructible<_Equal>::value); + noexcept(_S_nothrow_move()); _Hashtable(_Hashtable&&, __node_alloc_type&&, false_type /* alloc always equal */); @@ -508,19 +517,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // Use delegating constructors. _Hashtable(_Hashtable&& __ht) - noexcept( noexcept( - _Hashtable(std::declval<_Hashtable>(), - std::declval<__node_alloc_type>(), - true_type{})) ) + noexcept(_S_nothrow_move()) : _Hashtable(std::move(__ht), std::move(__ht._M_node_allocator()), true_type{}) { } _Hashtable(_Hashtable&& __ht, const allocator_type& __a) - noexcept( noexcept( - _Hashtable(std::declval<_Hashtable>(), - std::declval<__node_alloc_type>(), - typename __node_alloc_traits::is_always_equal{})) ) + noexcept(_S_nothrow_move<__node_alloc_traits::_S_always_equal()>()) : _Hashtable(std::move(__ht), __node_alloc_type(__a), typename __node_alloc_traits::is_always_equal{}) { } @@ -1400,8 +1403,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>:: _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a, true_type /* alloc always equal */) - noexcept(std::is_nothrow_copy_constructible<_Hash>::value && - std::is_nothrow_copy_constructible<_Equal>::value) + noexcept(_S_nothrow_move()) : __hashtable_base(__ht), __map_base(__ht), __rehash_base(__ht), diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/cons/noexcept_move_construct.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/noexcept_move_construct.cc index 96245aa4c88..015646adf23 100644 --- a/libstdc++-v3/testsuite/23_containers/unordered_map/cons/noexcept_move_construct.cc +++ b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/noexcept_move_construct.cc @@ -40,7 +40,7 @@ struct not_noexcept_copy_cons_hash using type2 = std::unordered_map; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); @@ -59,7 +59,7 @@ using type3 = std::unordered_map, not_noexcept_copy_cons_equal_to>; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/noexcept_move_construct.cc b/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/noexcept_move_construct.cc index efc8d337e7e..1e0b1059d7d 100644 --- a/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/noexcept_move_construct.cc +++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/cons/noexcept_move_construct.cc @@ -40,7 +40,7 @@ struct not_noexcept_copy_cons_hash using type2 = std::unordered_multimap; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); @@ -59,7 +59,7 @@ using type3 = std::unordered_multimap, not_noexcept_copy_cons_equal_to>; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/noexcept_move_construct.cc b/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/noexcept_move_construct.cc index cc2a8e31051..3e603802f13 100644 --- a/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/noexcept_move_construct.cc +++ b/libstdc++-v3/testsuite/23_containers/unordered_multiset/cons/noexcept_move_construct.cc @@ -40,7 +40,7 @@ struct not_noexcept_copy_cons_hash using type2 = std::unordered_multiset; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); @@ -59,7 +59,7 @@ using type3 = std::unordered_multiset, not_noexcept_copy_cons_equal_to>; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/cons/noexcept_move_construct.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/cons/noexcept_move_construct.cc index f68095302d5..28cb539e9f5 100644 --- a/libstdc++-v3/testsuite/23_containers/unordered_set/cons/noexcept_move_construct.cc +++ b/libstdc++-v3/testsuite/23_containers/unordered_set/cons/noexcept_move_construct.cc @@ -40,7 +40,7 @@ struct not_noexcept_copy_cons_hash using type2 = std::unordered_set; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" ); @@ -59,7 +59,7 @@ using type3 = std::unordered_set, not_noexcept_copy_cons_equal_to>; static_assert( !std::is_nothrow_move_constructible::value, - "noexcept move constructor" ); + "not noexcept move constructor" ); static_assert( !std::is_nothrow_constructible::value, "not noexcept move constructor with allocator" );