// Node handles for containers -*- C++ -*- // Copyright (C) 2016-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/node_handle.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. * @headername{map,set,unordered_map,unordered_set} */ #ifndef _NODE_HANDLE #define _NODE_HANDLE 1 #pragma GCC system_header #if __cplusplus > 201402L # define __cpp_lib_node_extract 201606 #include <optional> #include <bits/alloc_traits.h> #include <bits/ptr_traits.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /// Base class for node handle types of maps and sets. template<typename _Val, typename _NodeAlloc> class _Node_handle_common { using _AllocTraits = allocator_traits<_NodeAlloc>; public: using allocator_type = __alloc_rebind<_NodeAlloc, _Val>; allocator_type get_allocator() const noexcept { __glibcxx_assert(!this->empty()); return allocator_type(*_M_alloc); } explicit operator bool() const noexcept { return _M_ptr != nullptr; } [[nodiscard]] bool empty() const noexcept { return _M_ptr == nullptr; } protected: constexpr _Node_handle_common() noexcept : _M_ptr(), _M_alloc() {} ~_Node_handle_common() { _M_destroy(); } _Node_handle_common(_Node_handle_common&& __nh) noexcept : _M_ptr(__nh._M_ptr), _M_alloc(std::move(__nh._M_alloc)) { __nh._M_ptr = nullptr; __nh._M_alloc = nullopt; } _Node_handle_common& operator=(_Node_handle_common&& __nh) noexcept { _M_destroy(); _M_ptr = __nh._M_ptr; if constexpr (is_move_assignable_v<_NodeAlloc>) { if (_AllocTraits::propagate_on_container_move_assignment::value || !this->_M_alloc) this->_M_alloc = std::move(__nh._M_alloc); else { __glibcxx_assert(this->_M_alloc == __nh._M_alloc); } } else { __glibcxx_assert(_M_alloc); } __nh._M_ptr = nullptr; __nh._M_alloc = nullopt; return *this; } _Node_handle_common(typename _AllocTraits::pointer __ptr, const _NodeAlloc& __alloc) : _M_ptr(__ptr), _M_alloc(__alloc) { } void _M_swap(_Node_handle_common& __nh) noexcept { using std::swap; swap(_M_ptr, __nh._M_ptr); if (_AllocTraits::propagate_on_container_swap::value || !_M_alloc || !__nh._M_alloc) _M_alloc.swap(__nh._M_alloc); else { __glibcxx_assert(_M_alloc == __nh._M_alloc); } } private: void _M_destroy() noexcept { if (_M_ptr != nullptr) { allocator_type __alloc(*_M_alloc); allocator_traits<allocator_type>::destroy(__alloc, _M_ptr->_M_valptr()); _AllocTraits::deallocate(*_M_alloc, _M_ptr, 1); } } protected: typename _AllocTraits::pointer _M_ptr; private: optional<_NodeAlloc> _M_alloc; template<typename _Key2, typename _Value2, typename _KeyOfValue, typename _Compare, typename _ValueAlloc> friend class _Rb_tree; }; /// Node handle type for maps. template<typename _Key, typename _Value, typename _NodeAlloc> class _Node_handle : public _Node_handle_common<_Value, _NodeAlloc> { public: constexpr _Node_handle() noexcept = default; ~_Node_handle() = default; _Node_handle(_Node_handle&&) noexcept = default; _Node_handle& operator=(_Node_handle&&) noexcept = default; using key_type = _Key; using mapped_type = typename _Value::second_type; key_type& key() const noexcept { __glibcxx_assert(!this->empty()); return *_M_pkey; } mapped_type& mapped() const noexcept { __glibcxx_assert(!this->empty()); return *_M_pmapped; } void swap(_Node_handle& __nh) noexcept { this->_M_swap(__nh); using std::swap; swap(_M_pkey, __nh._M_pkey); swap(_M_pmapped, __nh._M_pmapped); } friend void swap(_Node_handle& __x, _Node_handle& __y) noexcept(noexcept(__x.swap(__y))) { __x.swap(__y); } private: using _AllocTraits = allocator_traits<_NodeAlloc>; _Node_handle(typename _AllocTraits::pointer __ptr, const _NodeAlloc& __alloc) : _Node_handle_common<_Value, _NodeAlloc>(__ptr, __alloc) { if (__ptr) { auto& __key = const_cast<_Key&>(__ptr->_M_valptr()->first); _M_pkey = _S_pointer_to(__key); _M_pmapped = _S_pointer_to(__ptr->_M_valptr()->second); } else { _M_pkey = nullptr; _M_pmapped = nullptr; } } template<typename _Tp> using __pointer = __ptr_rebind<typename _AllocTraits::pointer, remove_reference_t<_Tp>>; __pointer<_Key> _M_pkey = nullptr; __pointer<typename _Value::second_type> _M_pmapped = nullptr; template<typename _Tp> __pointer<_Tp> _S_pointer_to(_Tp& __obj) { return pointer_traits<__pointer<_Tp>>::pointer_to(__obj); } const key_type& _M_key() const noexcept { return key(); } template<typename _Key2, typename _Value2, typename _KeyOfValue, typename _Compare, typename _ValueAlloc> friend class _Rb_tree; template<typename _Key2, typename _Value2, typename _ValueAlloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> friend class _Hashtable; }; /// Node handle type for sets. template<typename _Value, typename _NodeAlloc> class _Node_handle<_Value, _Value, _NodeAlloc> : public _Node_handle_common<_Value, _NodeAlloc> { public: constexpr _Node_handle() noexcept = default; ~_Node_handle() = default; _Node_handle(_Node_handle&&) noexcept = default; _Node_handle& operator=(_Node_handle&&) noexcept = default; using value_type = _Value; value_type& value() const noexcept { __glibcxx_assert(!this->empty()); return *this->_M_ptr->_M_valptr(); } void swap(_Node_handle& __nh) noexcept { this->_M_swap(__nh); } friend void swap(_Node_handle& __x, _Node_handle& __y) noexcept(noexcept(__x.swap(__y))) { __x.swap(__y); } private: using _AllocTraits = allocator_traits<_NodeAlloc>; _Node_handle(typename _AllocTraits::pointer __ptr, const _NodeAlloc& __alloc) : _Node_handle_common<_Value, _NodeAlloc>(__ptr, __alloc) { } const value_type& _M_key() const noexcept { return value(); } template<typename _Key, typename _Val, typename _KeyOfValue, typename _Compare, typename _Alloc> friend class _Rb_tree; template<typename _Key2, typename _Value2, typename _ValueAlloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> friend class _Hashtable; }; /// Return type of insert(node_handle&&) on unique maps/sets. template<typename _Iterator, typename _NodeHandle> struct _Node_insert_return { _Iterator position = _Iterator(); bool inserted = false; _NodeHandle node; }; _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++17 #endif