Fix LWG issue 2469 - Use piecewise construction in map::operator[]. map's allocator may only be used to construct objects of 'value_type', or in this case 'pair<const Key, Value>'. In order to respect this requirement in operator[], which requires default constructing the 'mapped_type', we have to use pair's piecewise constructor with '(tuple<Kep>, tuple<>)'. Unfortunately we still need to provide a fallback implementation for C++03 since we don't have <tuple>. Even worse this fallback is the last remaining user of '__hash_map_node_destructor' and '__construct_node_with_key'. This patch also switches try_emplace over to __tree.__emplace_unique_key_args. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@264989 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/map b/include/map index a459146..29d068a 100644 --- a/include/map +++ b/include/map
@@ -1026,7 +1026,7 @@ size_type max_size() const _NOEXCEPT {return __tree_.max_size();} mapped_type& operator[](const key_type& __k); -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES +#ifndef _LIBCPP_CXX03_LANG mapped_type& operator[](key_type&& __k); #endif @@ -1105,62 +1105,45 @@ #endif // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS #if _LIBCPP_STD_VER > 14 -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES -#ifndef _LIBCPP_HAS_NO_VARIADICS + template <class... _Args> _LIBCPP_INLINE_VISIBILITY pair<iterator, bool> try_emplace(const key_type& __k, _Args&&... __args) { - iterator __p = lower_bound(__k); - if ( __p != end() && !key_comp()(__k, __p->first)) - return _VSTD::make_pair(__p, false); - else - return _VSTD::make_pair( - emplace_hint(__p, - _VSTD::piecewise_construct, _VSTD::forward_as_tuple(__k), - _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)), - true); + return __tree_.__emplace_unique_key_args(__k, + _VSTD::piecewise_construct, + _VSTD::forward_as_tuple(__k), + _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); } template <class... _Args> _LIBCPP_INLINE_VISIBILITY pair<iterator, bool> try_emplace(key_type&& __k, _Args&&... __args) { - iterator __p = lower_bound(__k); - if ( __p != end() && !key_comp()(__k, __p->first)) - return _VSTD::make_pair(__p, false); - else - return _VSTD::make_pair( - emplace_hint(__p, - _VSTD::piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__k)), - _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)), - true); + return __tree_.__emplace_unique_key_args(__k, + _VSTD::piecewise_construct, + _VSTD::forward_as_tuple(_VSTD::move(__k)), + _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); } template <class... _Args> _LIBCPP_INLINE_VISIBILITY iterator try_emplace(const_iterator __h, const key_type& __k, _Args&&... __args) { - iterator __p = lower_bound(__k); - if ( __p != end() && !key_comp()(__k, __p->first)) - return __p; - else - return emplace_hint(__p, - _VSTD::piecewise_construct, _VSTD::forward_as_tuple(__k), - _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); + return __tree_.__emplace_hint_unique_key_args(__h.__i_, __k, + _VSTD::piecewise_construct, + _VSTD::forward_as_tuple(__k), + _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); } template <class... _Args> _LIBCPP_INLINE_VISIBILITY iterator try_emplace(const_iterator __h, key_type&& __k, _Args&&... __args) { - iterator __p = lower_bound(__k); - if ( __p != end() && !key_comp()(__k, __p->first)) - return __p; - else - return emplace_hint(__p, - _VSTD::piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__k)), - _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); + return __tree_.__emplace_hint_unique_key_args(__h.__i_, __k, + _VSTD::piecewise_construct, + _VSTD::forward_as_tuple(_VSTD::move(__k)), + _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); } template <class _Vp> @@ -1175,7 +1158,7 @@ } return _VSTD::make_pair(emplace_hint(__p, __k, _VSTD::forward<_Vp>(__v)), true); } - + template <class _Vp> _LIBCPP_INLINE_VISIBILITY pair<iterator, bool> insert_or_assign(key_type&& __k, _Vp&& __v) @@ -1214,8 +1197,7 @@ } return emplace_hint(__h, _VSTD::move(__k), _VSTD::forward<_Vp>(__v)); } -#endif -#endif + #endif _LIBCPP_INLINE_VISIBILITY @@ -1321,11 +1303,9 @@ typedef __map_node_destructor<__node_allocator> _Dp; typedef unique_ptr<__node, _Dp> __node_holder; -#ifndef _LIBCPP_CXX03_LANG - __node_holder __construct_node_with_key(key_type&& __k); -#endif - +#ifdef _LIBCPP_CXX03_LANG __node_holder __construct_node_with_key(const key_type& __k); +#endif __node_base_pointer const& __find_equal_key(__node_base_pointer& __parent, const key_type& __k) const; @@ -1400,22 +1380,11 @@ } } - -template <class _Key, class _Tp, class _Compare, class _Allocator> -typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder -map<_Key, _Tp, _Compare, _Allocator>::__construct_node_with_key(key_type&& __k) -{ - __node_allocator& __na = __tree_.__node_alloc(); - __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); - __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.first), _VSTD::move(__k)); - __h.get_deleter().__first_constructed = true; - __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.second)); - __h.get_deleter().__second_constructed = true; - return __h; -} - #endif // !_LIBCPP_CXX03_LANG + +#ifdef _LIBCPP_CXX03_LANG + template <class _Key, class _Tp, class _Compare, class _Allocator> typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder map<_Key, _Tp, _Compare, _Allocator>::__construct_node_with_key(const key_type& __k) @@ -1445,25 +1414,29 @@ return __r->__value_.__cc.second; } -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES +#else + +template <class _Key, class _Tp, class _Compare, class _Allocator> +_Tp& +map<_Key, _Tp, _Compare, _Allocator>::operator[](const key_type& __k) +{ + return __tree_.__emplace_unique_key_args(__k, + _VSTD::piecewise_construct, + _VSTD::forward_as_tuple(__k), + _VSTD::forward_as_tuple()).first->__cc.second; +} template <class _Key, class _Tp, class _Compare, class _Allocator> _Tp& map<_Key, _Tp, _Compare, _Allocator>::operator[](key_type&& __k) { - __node_base_pointer __parent; - __node_base_pointer& __child = __find_equal_key(__parent, __k); - __node_pointer __r = static_cast<__node_pointer>(__child); - if (__child == nullptr) - { - __node_holder __h = __construct_node_with_key(_VSTD::move(__k)); - __tree_.__insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); - __r = __h.release(); - } - return __r->__value_.__cc.second; + return __tree_.__emplace_unique_key_args(__k, + _VSTD::piecewise_construct, + _VSTD::forward_as_tuple(_VSTD::move(__k)), + _VSTD::forward_as_tuple()).first->__cc.second; } -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES +#endif // !_LIBCPP_CXX03_LANG template <class _Key, class _Tp, class _Compare, class _Allocator> _Tp& 