| // <forward_list.h> -*- C++ -*- |
| |
| // Copyright (C) 2008-2025 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/forward_list.h |
| * This is an internal header file, included by other library headers. |
| * Do not attempt to use it directly. @headername{forward_list} |
| */ |
| |
| #ifndef _FORWARD_LIST_H |
| #define _FORWARD_LIST_H 1 |
| |
| #ifdef _GLIBCXX_SYSHDR |
| #pragma GCC system_header |
| #endif |
| |
| #include <initializer_list> |
| #include <bits/stl_iterator_base_types.h> |
| #include <bits/stl_iterator.h> |
| #include <bits/stl_algobase.h> |
| #include <bits/stl_function.h> |
| #include <bits/allocator.h> |
| #include <bits/allocated_ptr.h> |
| #include <bits/ptr_traits.h> |
| #include <debug/assertions.h> |
| #include <ext/alloc_traits.h> |
| #include <ext/aligned_buffer.h> |
| #include <debug/assertions.h> |
| #if __glibcxx_containers_ranges // C++ >= 23 |
| # include <bits/ranges_base.h> // ranges::begin, ranges::distance etc. |
| # include <bits/ranges_util.h> // ranges::subrange |
| #endif |
| |
| #if ! defined _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| # define _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST 1 |
| #endif |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| _GLIBCXX_BEGIN_NAMESPACE_CONTAINER |
| |
| /** |
| * @brief A helper basic node class for %forward_list. |
| * |
| * This is just a linked list with nothing inside it. |
| * There are purely list shuffling utility methods here. |
| */ |
| struct _Fwd_list_node_base |
| { |
| using _Base_ptr = _Fwd_list_node_base*; |
| |
| _Fwd_list_node_base() = default; |
| _Fwd_list_node_base(_Fwd_list_node_base&& __x) noexcept |
| : _M_next(__x._M_next) |
| { __x._M_next = nullptr; } |
| |
| _Fwd_list_node_base(const _Fwd_list_node_base&) = delete; |
| _Fwd_list_node_base& operator=(const _Fwd_list_node_base&) = delete; |
| |
| _Fwd_list_node_base& |
| operator=(_Fwd_list_node_base&& __x) noexcept |
| { |
| _M_next = __x._M_next; |
| __x._M_next = nullptr; |
| return *this; |
| } |
| |
| _Fwd_list_node_base* _M_next = nullptr; |
| |
| _Fwd_list_node_base* |
| _M_transfer_after(_Fwd_list_node_base* __begin, |
| _Fwd_list_node_base* __end) noexcept |
| { |
| _Fwd_list_node_base* __keep = __begin->_M_next; |
| if (__end) |
| { |
| __begin->_M_next = __end->_M_next; |
| __end->_M_next = _M_next; |
| } |
| else |
| __begin->_M_next = nullptr; |
| _M_next = __keep; |
| return __end; |
| } |
| |
| void |
| _M_reverse_after() noexcept |
| { |
| _Fwd_list_node_base* __tail = _M_next; |
| if (!__tail) |
| return; |
| while (_Fwd_list_node_base* __temp = __tail->_M_next) |
| { |
| _Fwd_list_node_base* __keep = _M_next; |
| _M_next = __temp; |
| __tail->_M_next = __temp->_M_next; |
| _M_next->_M_next = __keep; |
| } |
| } |
| |
| _Fwd_list_node_base* _M_base_ptr() { return this; } |
| const _Fwd_list_node_base* _M_base_ptr() const { return this; } |
| }; |
| |
| /** |
| * @brief A helper node class for %forward_list. |
| * This is just a linked list with uninitialized storage for a |
| * data value in each node. |
| * There is a sorting utility method. |
| */ |
| template<typename _Tp> |
| struct _Fwd_list_node |
| : public _Fwd_list_node_base |
| { |
| using _Node_ptr = _Fwd_list_node*; |
| |
| _Fwd_list_node() = default; |
| |
| __gnu_cxx::__aligned_buffer<_Tp> _M_storage; |
| |
| _Tp* |
| _M_valptr() noexcept |
| { return _M_storage._M_ptr(); } |
| |
| const _Tp* |
| _M_valptr() const noexcept |
| { return _M_storage._M_ptr(); } |
| |
| _Node_ptr |
| _M_node_ptr() |
| { return this; } |
| }; |
| |
| template<typename _Tp> struct _Fwd_list_const_iterator; |
| |
| /** |
| * @brief A forward_list::iterator. |
| * |
| * All the functions are op overloads. |
| */ |
| template<typename _Tp> |
| struct _Fwd_list_iterator |
| { |
| typedef _Fwd_list_iterator<_Tp> _Self; |
| typedef _Fwd_list_node<_Tp> _Node; |
| |
| typedef _Tp value_type; |
| typedef _Tp* pointer; |
| typedef _Tp& reference; |
| typedef ptrdiff_t difference_type; |
| typedef std::forward_iterator_tag iterator_category; |
| |
| _Fwd_list_iterator() noexcept |
| : _M_node() { } |
| |
| explicit |
| _Fwd_list_iterator(_Fwd_list_node_base* __n) noexcept |
| : _M_node(__n) { } |
| |
| [[__nodiscard__]] |
| reference |
| operator*() const noexcept |
| { return *static_cast<_Node*>(this->_M_node)->_M_valptr(); } |
| |
| [[__nodiscard__]] |
| pointer |
| operator->() const noexcept |
| { return static_cast<_Node*>(this->_M_node)->_M_valptr(); } |
| |
| _Self& |
| operator++() noexcept |
| { |
| _M_node = _M_node->_M_next; |
| return *this; |
| } |
| |
| _Self |
| operator++(int) noexcept |
| { |
| _Self __tmp(*this); |
| _M_node = _M_node->_M_next; |
| return __tmp; |
| } |
| |
| /** |
| * @brief Forward list iterator equality comparison. |
| */ |
| [[__nodiscard__]] |
| friend bool |
| operator==(const _Self& __x, const _Self& __y) noexcept |
| { return __x._M_node == __y._M_node; } |
| |
| #if __cpp_impl_three_way_comparison < 201907L |
| /** |
| * @brief Forward list iterator inequality comparison. |
| */ |
| [[__nodiscard__]] |
| friend bool |
| operator!=(const _Self& __x, const _Self& __y) noexcept |
| { return __x._M_node != __y._M_node; } |
| #endif |
| |
| private: |
| template<typename, typename> |
| friend class forward_list; |
| template<typename, typename> |
| friend struct _Fwd_list_base; |
| friend struct _Fwd_list_const_iterator<_Tp>; |
| |
| _Self |
| _M_next() const noexcept |
| { |
| if (_M_node) |
| return _Fwd_list_iterator(_M_node->_M_next); |
| else |
| return _Fwd_list_iterator(nullptr); |
| } |
| |
| _Fwd_list_node_base* _M_node; |
| }; |
| |
| /** |
| * @brief A forward_list::const_iterator. |
| * |
| * All the functions are op overloads. |
| */ |
| template<typename _Tp> |
| struct _Fwd_list_const_iterator |
| { |
| typedef _Fwd_list_const_iterator<_Tp> _Self; |
| typedef const _Fwd_list_node<_Tp> _Node; |
| typedef _Fwd_list_iterator<_Tp> iterator; |
| |
| typedef _Tp value_type; |
| typedef const _Tp* pointer; |
| typedef const _Tp& reference; |
| typedef ptrdiff_t difference_type; |
| typedef std::forward_iterator_tag iterator_category; |
| |
| _Fwd_list_const_iterator() noexcept |
| : _M_node() { } |
| |
| explicit |
| _Fwd_list_const_iterator(const _Fwd_list_node_base* __n) noexcept |
| : _M_node(__n) { } |
| |
| _Fwd_list_const_iterator(const iterator& __iter) noexcept |
| : _M_node(__iter._M_node) { } |
| |
| [[__nodiscard__]] |
| reference |
| operator*() const noexcept |
| { return *static_cast<_Node*>(this->_M_node)->_M_valptr(); } |
| |
| [[__nodiscard__]] |
| pointer |
| operator->() const noexcept |
| { return static_cast<_Node*>(this->_M_node)->_M_valptr(); } |
| |
| _Self& |
| operator++() noexcept |
| { |
| _M_node = _M_node->_M_next; |
| return *this; |
| } |
| |
| _Self |
| operator++(int) noexcept |
| { |
| _Self __tmp(*this); |
| _M_node = _M_node->_M_next; |
| return __tmp; |
| } |
| |
| /** |
| * @brief Forward list const_iterator equality comparison. |
| */ |
| [[__nodiscard__]] |
| friend bool |
| operator==(const _Self& __x, const _Self& __y) noexcept |
| { return __x._M_node == __y._M_node; } |
| |
| #if __cpp_impl_three_way_comparison < 201907L |
| /** |
| * @brief Forward list const_iterator inequality comparison. |
| */ |
| [[__nodiscard__]] |
| friend bool |
| operator!=(const _Self& __x, const _Self& __y) noexcept |
| { return __x._M_node != __y._M_node; } |
| #endif |
| |
| private: |
| template<typename, typename> |
| friend class forward_list; |
| template<typename, typename> |
| friend struct _Fwd_list_base; |
| |
| _Self |
| _M_next() const noexcept |
| { |
| if (this->_M_node) |
| return _Fwd_list_const_iterator(_M_node->_M_next); |
| else |
| return _Fwd_list_const_iterator(nullptr); |
| } |
| |
| _Fwd_list_iterator<_Tp> |
| _M_const_cast() const noexcept |
| { |
| return _Fwd_list_iterator<_Tp>( |
| const_cast<_Fwd_list_node_base*>(_M_node)); |
| } |
| |
| const _Fwd_list_node_base* _M_node; |
| }; |
| |
| template<typename _Tp, typename _Allocator> class forward_list; |
| template<typename _Tp, typename _Allocator> struct _Fwd_list_base; |
| |
| namespace __fwdlist |
| { |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| /// The node-base type for allocators that use fancy pointers. |
| template<typename _VoidPtr> |
| struct _Node_base |
| { |
| using _Base_ptr = __ptr_rebind<_VoidPtr, _Node_base>; |
| |
| _Node_base() = default; |
| |
| _Node_base(_Node_base&& __x) noexcept |
| : _M_next(__x._M_next) |
| { __x._M_next = nullptr; } |
| |
| _Node_base(const _Node_base&) = delete; |
| _Node_base& operator=(const _Node_base&) = delete; |
| |
| _Node_base& |
| operator=(_Node_base&& __x) noexcept |
| { |
| _M_next = __x._M_next; |
| __x._M_next = nullptr; |
| return *this; |
| } |
| |
| _Base_ptr _M_next = nullptr; |
| |
| // Splice (begin,end) before _M_next. |
| _Base_ptr |
| _M_transfer_after(_Base_ptr __begin, _Base_ptr __end) noexcept |
| { |
| _Base_ptr __keep = __begin->_M_next; |
| if (__end) |
| { |
| __begin->_M_next = __end->_M_next; |
| __end->_M_next = _M_next; |
| } |
| else |
| __begin->_M_next = nullptr; |
| _M_next = __keep; |
| return __end; |
| } |
| |
| void |
| _M_reverse_after() noexcept |
| { |
| _Base_ptr __tail = _M_next; |
| if (!__tail) |
| return; |
| while (_Base_ptr __temp = __tail->_M_next) |
| { |
| _Base_ptr __keep = _M_next; |
| _M_next = __temp; |
| __tail->_M_next = __temp->_M_next; |
| _M_next->_M_next = __keep; |
| } |
| } |
| |
| // This is not const-correct, but it's only used in a const access path |
| // by std::forward_list::empty(), where it doesn't escape, and by |
| // std::forward_list::before_begin() const, where the pointer is used |
| // to initialize a const_iterator and so constness is restored. |
| _Base_ptr |
| _M_base_ptr() const |
| { |
| return pointer_traits<_Base_ptr>:: |
| pointer_to(const_cast<_Node_base&>(*this)); |
| } |
| }; |
| |
| /** |
| * @brief A helper node class for %forward_list. |
| */ |
| template<typename _ValPtr> |
| struct _Node |
| : public _Node_base<__ptr_rebind<_ValPtr, void>> |
| { |
| using value_type = typename pointer_traits<_ValPtr>::element_type; |
| using _Node_ptr = __ptr_rebind<_ValPtr, _Node>; |
| |
| _Node() noexcept { } |
| ~_Node() { } |
| _Node(_Node&&) = delete; |
| |
| union _Uninit_storage |
| { |
| _Uninit_storage() noexcept { } |
| ~_Uninit_storage() { } |
| |
| #if ! _GLIBCXX_INLINE_VERSION |
| // For ABI compatibility we need to overalign this member. |
| alignas(__alignof__(value_type)) // XXX GLIBCXX_ABI Deprecated |
| #endif |
| value_type _M_data; |
| }; |
| _Uninit_storage _M_u; |
| |
| value_type* |
| _M_valptr() noexcept |
| { return std::__addressof(_M_u._M_data); } |
| |
| const value_type* |
| _M_valptr() const noexcept |
| { return std::__addressof(_M_u._M_data); } |
| |
| _Node_ptr |
| _M_node_ptr() |
| { return pointer_traits<_Node_ptr>::pointer_to(*this); } |
| }; |
| |
| /// A forward_list iterator when the allocator uses fancy pointers. |
| template<bool _Const, typename _Ptr> |
| class _Iterator |
| { |
| using _Node = __fwdlist::_Node<_Ptr>; |
| using _Base_ptr |
| = typename __fwdlist::_Node_base<__ptr_rebind<_Ptr, void>>::_Base_ptr; |
| |
| template<typename _Tp> |
| using __maybe_const = __conditional_t<_Const, const _Tp, _Tp>; |
| |
| public: |
| using value_type = typename pointer_traits<_Ptr>::element_type; |
| using difference_type = ptrdiff_t; |
| using iterator_category = forward_iterator_tag; |
| using pointer = __maybe_const<value_type>*; |
| using reference = __maybe_const<value_type>&; |
| |
| constexpr _Iterator() noexcept : _M_node() { } |
| |
| _Iterator(const _Iterator&) = default; |
| _Iterator& operator=(const _Iterator&) = default; |
| |
| #ifdef __glibcxx_concepts |
| constexpr |
| _Iterator(const _Iterator<false, _Ptr>& __i) requires _Const |
| #else |
| template<bool _OtherConst, |
| typename = __enable_if_t<_Const && !_OtherConst>> |
| constexpr |
| _Iterator(const _Iterator<_OtherConst, _Ptr>& __i) |
| #endif |
| : _M_node(__i._M_node) { } |
| |
| constexpr explicit |
| _Iterator(_Base_ptr __x) noexcept |
| : _M_node(__x) { } |
| |
| [[__nodiscard__]] |
| constexpr reference |
| operator*() const noexcept |
| { return static_cast<_Node&>(*this->_M_node)._M_u._M_data; } |
| |
| [[__nodiscard__]] |
| constexpr pointer |
| operator->() const noexcept |
| { return static_cast<_Node&>(*this->_M_node)._M_valptr(); } |
| |
| _GLIBCXX14_CONSTEXPR _Iterator& |
| operator++() noexcept |
| { |
| _M_node = _M_node->_M_next; |
| return *this; |
| } |
| |
| _GLIBCXX14_CONSTEXPR _Iterator |
| operator++(int) noexcept |
| { |
| _Iterator __tmp(*this); |
| _M_node = _M_node->_M_next; |
| return __tmp; |
| } |
| |
| /** |
| * @brief Forward list iterator equality comparison. |
| */ |
| [[__nodiscard__]] |
| friend constexpr bool |
| operator==(const _Iterator& __x, const _Iterator& __y) noexcept |
| { return __x._M_node == __y._M_node; } |
| |
| #if __cpp_impl_three_way_comparison < 201907L |
| /** |
| * @brief Forward list iterator inequality comparison. |
| */ |
| [[__nodiscard__]] |
| friend constexpr bool |
| operator!=(const _Iterator& __x, const _Iterator& __y) noexcept |
| { return __x._M_node != __y._M_node; } |
| #endif |
| |
| private: |
| template<typename _Tp, typename _Allocator> |
| friend class _GLIBCXX_STD_C::forward_list; |
| template<typename _Tp, typename _Allocator> |
| friend struct _GLIBCXX_STD_C::_Fwd_list_base; |
| |
| constexpr _Iterator<false, _Ptr> |
| _M_const_cast() const noexcept |
| { return _Iterator<false, _Ptr>(_M_node); } |
| |
| friend _Iterator<!_Const, _Ptr>; |
| |
| constexpr _Iterator |
| _M_next() const noexcept |
| { return _Iterator(_M_node ? _M_node->_M_next : nullptr); } |
| |
| _Base_ptr _M_node; |
| }; |
| #endif // USE_ALLOC_PTR_FOR_FWD_LIST |
| |
| // Determine the node and iterator types used by std::forward_list. |
| template<typename _Tp, typename _Ptr> |
| struct _Node_traits; |
| |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_LIST <= 9000 |
| // Specialization for the simple case where the allocator's pointer type |
| // is the same type as value_type*. |
| // For ABI compatibility we can't change the types used for this case. |
| template<typename _Tp> |
| struct _Node_traits<_Tp, _Tp*> |
| { |
| using _Node_base = _Fwd_list_node_base; |
| using _Node = _Fwd_list_node<_Tp>; |
| using _Iterator = _Fwd_list_iterator<_Tp>; |
| using _Const_iterator = _Fwd_list_const_iterator<_Tp>; |
| }; |
| #endif |
| |
| #if ! _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| // Always use the T* specialization. |
| template<typename _Tp, typename _Ptr> |
| struct _Node_traits |
| : _Node_traits<_Tp, _Tp*> |
| { }; |
| #else |
| // Primary template used when the allocator uses fancy pointers. |
| template<typename _Tp, typename _Ptr> |
| struct _Node_traits |
| { |
| private: |
| using _VoidPtr = __ptr_rebind<_Ptr, void>; |
| using _ValPtr = __ptr_rebind<_Ptr, _Tp>; |
| |
| public: |
| using _Node_base = __fwdlist::_Node_base<_VoidPtr>; |
| using _Node = __fwdlist::_Node<_ValPtr>; |
| using _Iterator = __fwdlist::_Iterator<false, _ValPtr>; |
| using _Const_iterator = __fwdlist::_Iterator<true, _ValPtr>; |
| }; |
| #endif // USE_ALLOC_PTR_FOR_FWD_LIST |
| } // namespace __fwdlist |
| |
| /** |
| * @brief Base class for %forward_list. |
| */ |
| template<typename _Tp, typename _Alloc> |
| struct _Fwd_list_base |
| { |
| #if __cplusplus > 201703L || defined __STRICT_ANSI__ |
| // The static_assert in forward_list ensures _Alloc::value_type is _Tp. |
| using pointer = typename allocator_traits<_Alloc>::pointer; |
| #else |
| using _Tp_alloc_traits |
| = typename allocator_traits<_Alloc>::template rebind_traits<_Tp>; |
| using pointer = typename _Tp_alloc_traits::pointer; |
| #endif |
| |
| protected: |
| using _Node_traits = __fwdlist::_Node_traits<_Tp, pointer>; |
| using _Node = typename _Node_traits::_Node; |
| using _Node_alloc_type = __alloc_rebind<_Alloc, _Node>; |
| using _Node_alloc_traits = __gnu_cxx::__alloc_traits<_Node_alloc_type>; |
| using _Node_ptr = typename _Node_alloc_traits::pointer; |
| using _Base_ptr = typename _Node_traits::_Node_base::_Base_ptr; |
| |
| struct _Fwd_list_impl |
| : public _Node_alloc_type |
| { |
| typename _Node_traits::_Node_base _M_head; |
| |
| _Fwd_list_impl() |
| noexcept(is_nothrow_default_constructible<_Node_alloc_type>::value) |
| : _Node_alloc_type(), _M_head() |
| { } |
| |
| _Fwd_list_impl(_Fwd_list_impl&&) = default; |
| |
| _Fwd_list_impl(_Fwd_list_impl&& __fl, _Node_alloc_type&& __a) |
| : _Node_alloc_type(std::move(__a)), _M_head(std::move(__fl._M_head)) |
| { } |
| |
| _Fwd_list_impl(_Node_alloc_type&& __a) |
| : _Node_alloc_type(std::move(__a)), _M_head() |
| { } |
| }; |
| |
| _Fwd_list_impl _M_impl; |
| |
| public: |
| using iterator = typename _Node_traits::_Iterator; |
| using const_iterator = typename _Node_traits::_Const_iterator; |
| |
| _Node_alloc_type& |
| _M_get_Node_allocator() noexcept |
| { return this->_M_impl; } |
| |
| const _Node_alloc_type& |
| _M_get_Node_allocator() const noexcept |
| { return this->_M_impl; } |
| |
| _Fwd_list_base() = default; |
| |
| _Fwd_list_base(_Node_alloc_type&& __a) |
| : _M_impl(std::move(__a)) { } |
| |
| // When allocators are always equal. |
| _Fwd_list_base(_Fwd_list_base&& __lst, _Node_alloc_type&& __a, |
| std::true_type) |
| : _M_impl(std::move(__lst._M_impl), std::move(__a)) |
| { } |
| |
| // When allocators are not always equal. |
| _Fwd_list_base(_Fwd_list_base&& __lst, _Node_alloc_type&& __a); |
| |
| _Fwd_list_base(_Fwd_list_base&&) = default; |
| |
| ~_Fwd_list_base() |
| { _M_erase_after(_M_impl._M_head._M_base_ptr(), nullptr); } |
| |
| protected: |
| #if ! _GLIBCXX_INLINE_VERSION |
| // XXX GLIBCXX_ABI Deprecated |
| _Node* |
| _M_get_node() |
| { |
| auto __ptr = _Node_alloc_traits::allocate(_M_get_Node_allocator(), 1); |
| return std::__to_address(__ptr); |
| } |
| #endif |
| |
| void |
| _M_put_node(_Node_ptr __p) |
| { |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| _Node_alloc_traits::deallocate(_M_get_Node_allocator(), __p, 1); |
| #else |
| typedef typename _Node_alloc_traits::pointer _Ptr; |
| auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__p); |
| _Node_alloc_traits::deallocate(_M_get_Node_allocator(), __ptr, 1); |
| #endif |
| } |
| |
| template<typename... _Args> |
| _Node_ptr |
| _M_create_node(_Args&&... __args) |
| { |
| auto& __alloc = _M_get_Node_allocator(); |
| auto __guard = std::__allocate_guarded_obj(__alloc); |
| _Node_alloc_traits::construct(__alloc, __guard->_M_valptr(), |
| std::forward<_Args>(__args)...); |
| auto __p = __guard.release(); |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| return __p; |
| #else |
| return std::__to_address(__p); |
| #endif |
| } |
| |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr |
| void |
| _M_destroy_node(_Node_ptr __p) |
| { |
| auto& __alloc = _M_get_Node_allocator(); |
| // Destroy the element |
| _Node_alloc_traits::destroy(__alloc, __p->_M_valptr()); |
| // Only destroy the node if the pointers require it. |
| if constexpr (!is_trivially_destructible<_Base_ptr>::value) |
| __p->~_Node(); |
| _M_put_node(__p); |
| } |
| #pragma GCC diagnostic pop |
| |
| template<typename... _Args> |
| _Base_ptr |
| _M_insert_after(const_iterator __pos, _Args&&... __args); |
| |
| _Base_ptr |
| _M_erase_after(_Base_ptr __pos); |
| |
| _Base_ptr |
| _M_erase_after(_Base_ptr __pos, _Base_ptr __last); |
| }; |
| |
| /** |
| * @brief A standard container with linear time access to elements, |
| * and fixed time insertion/deletion at any point in the sequence. |
| * |
| * @ingroup sequences |
| * @headerfile forward_list |
| * @since C++11 |
| * |
| * @tparam _Tp Type of element. |
| * @tparam _Alloc Allocator type, defaults to allocator<_Tp>. |
| * |
| * Meets the requirements of a <a href="tables.html#65">container</a>, a |
| * <a href="tables.html#67">sequence</a>, including the |
| * <a href="tables.html#68">optional sequence requirements</a> with the |
| * %exception of `at` and `operator[]`. |
| * |
| * This is a @e singly @e linked %list. Traversal up the |
| * %list requires linear time, but adding and removing elements (or |
| * @e nodes) is done in constant time, regardless of where the |
| * change takes place. Unlike std::vector and std::deque, |
| * random-access iterators are not provided, so subscripting (`[]`) |
| * access is not allowed. For algorithms which only need |
| * sequential access, this lack makes no difference. |
| * |
| * Also unlike the other standard containers, std::forward_list provides |
| * specialized algorithms %unique to linked lists, such as |
| * splicing, sorting, and in-place reversal. |
| */ |
| template<typename _Tp, typename _Alloc = allocator<_Tp>> |
| class forward_list : private _Fwd_list_base<_Tp, _Alloc> |
| { |
| static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value, |
| "std::forward_list must have a non-const, non-volatile value_type"); |
| #if __cplusplus > 201703L || defined __STRICT_ANSI__ |
| static_assert(is_same<typename _Alloc::value_type, _Tp>::value, |
| "std::forward_list must have the same value_type as its allocator"); |
| #endif |
| |
| private: |
| typedef _Fwd_list_base<_Tp, _Alloc> _Base; |
| typedef _Fwd_list_node_base _Node_base; |
| typedef typename _Base::_Node _Node; |
| typedef typename _Base::_Node_alloc_type _Node_alloc_type; |
| typedef typename _Base::_Node_alloc_traits _Node_alloc_traits; |
| typedef allocator_traits<__alloc_rebind<_Alloc, _Tp>> _Alloc_traits; |
| |
| public: |
| // types: |
| typedef _Tp value_type; |
| typedef typename _Alloc_traits::pointer pointer; |
| typedef typename _Alloc_traits::const_pointer const_pointer; |
| typedef value_type& reference; |
| typedef const value_type& const_reference; |
| |
| typedef typename _Base::iterator iterator; |
| typedef typename _Base::const_iterator const_iterator; |
| typedef std::size_t size_type; |
| typedef std::ptrdiff_t difference_type; |
| typedef _Alloc allocator_type; |
| |
| // 23.3.4.2 construct/copy/destroy: |
| |
| /** |
| * @brief Creates a %forward_list with no elements. |
| */ |
| forward_list() = default; |
| |
| /** |
| * @brief Creates a %forward_list with no elements. |
| * @param __al An allocator object. |
| */ |
| explicit |
| forward_list(const _Alloc& __al) noexcept |
| : _Base(_Node_alloc_type(__al)) |
| { } |
| |
| /** |
| * @brief Copy constructor with allocator argument. |
| * @param __list Input list to copy. |
| * @param __al An allocator object. |
| */ |
| forward_list(const forward_list& __list, |
| const __type_identity_t<_Alloc>& __al) |
| : _Base(_Node_alloc_type(__al)) |
| { _M_range_initialize(__list.begin(), __list.end()); } |
| |
| private: |
| forward_list(forward_list&& __list, _Node_alloc_type&& __al, |
| false_type) |
| : _Base(std::move(__list), std::move(__al)) |
| { |
| // If __list is not empty it means its allocator is not equal to __a, |
| // so we need to move from each element individually. |
| insert_after(cbefore_begin(), |
| std::__make_move_if_noexcept_iterator(__list.begin()), |
| std::__make_move_if_noexcept_iterator(__list.end())); |
| } |
| |
| forward_list(forward_list&& __list, _Node_alloc_type&& __al, |
| true_type) |
| noexcept |
| : _Base(std::move(__list), _Node_alloc_type(__al), true_type{}) |
| { } |
| |
| public: |
| /** |
| * @brief Move constructor with allocator argument. |
| * @param __list Input list to move. |
| * @param __al An allocator object. |
| */ |
| forward_list(forward_list&& __list, |
| const __type_identity_t<_Alloc>& __al) |
| noexcept(_Node_alloc_traits::_S_always_equal()) |
| : forward_list(std::move(__list), _Node_alloc_type(__al), |
| typename _Node_alloc_traits::is_always_equal{}) |
| { } |
| |
| /** |
| * @brief Creates a %forward_list with default constructed elements. |
| * @param __n The number of elements to initially create. |
| * @param __al An allocator object. |
| * |
| * This constructor creates the %forward_list with `__n` default |
| * constructed elements. |
| */ |
| explicit |
| forward_list(size_type __n, const _Alloc& __al = _Alloc()) |
| : _Base(_Node_alloc_type(__al)) |
| { _M_default_initialize(__n); } |
| |
| /** |
| * @brief Creates a %forward_list with copies of an exemplar element. |
| * @param __n The number of elements to initially create. |
| * @param __value An element to copy. |
| * @param __al An allocator object. |
| * |
| * This constructor fills the %forward_list with `__n` copies of |
| * `__value`. |
| */ |
| forward_list(size_type __n, const _Tp& __value, |
| const _Alloc& __al = _Alloc()) |
| : _Base(_Node_alloc_type(__al)) |
| { _M_fill_initialize(__n, __value); } |
| |
| /** |
| * @brief Builds a %forward_list from a range. |
| * @param __first An input iterator. |
| * @param __last An input iterator. |
| * @param __al An allocator object. |
| * |
| * Create a %forward_list consisting of copies of the elements from |
| * `[__first,__last)`. This is linear in N (where N is |
| * `distance(__first,__last)`). |
| */ |
| template<typename _InputIterator, |
| typename = std::_RequireInputIter<_InputIterator>> |
| forward_list(_InputIterator __first, _InputIterator __last, |
| const _Alloc& __al = _Alloc()) |
| : _Base(_Node_alloc_type(__al)) |
| { _M_range_initialize(__first, __last); } |
| |
| #if __glibcxx_containers_ranges // C++ >= 23 |
| /** |
| * @brief Construct a forward_list from a range. |
| * @param __rg An input range with elements that are convertible to |
| * the forward_list's value_type. |
| * @param __a An allocator. |
| * |
| * @since C++23 |
| */ |
| template<__detail::__container_compatible_range<_Tp> _Rg> |
| forward_list(from_range_t, _Rg&& __rg, const _Alloc& __a = _Alloc()) |
| : _Base(_Node_alloc_type(__a)) |
| { |
| auto __to = this->_M_impl._M_head._M_base_ptr(); |
| auto __first = ranges::begin(__rg); |
| const auto __last = ranges::end(__rg); |
| for (; __first != __last; ++__first) |
| { |
| __to->_M_next = this->_M_create_node(*__first)->_M_base_ptr(); |
| __to = __to->_M_next; |
| } |
| } |
| #endif // containers_ranges |
| |
| /** |
| * @brief The %forward_list copy constructor. |
| * @param __list A %forward_list of identical element and allocator |
| * types. |
| */ |
| forward_list(const forward_list& __list) |
| : _Base(_Node_alloc_traits::_S_select_on_copy( |
| __list._M_get_Node_allocator())) |
| { _M_range_initialize(__list.begin(), __list.end()); } |
| |
| /** |
| * @brief The %forward_list move constructor. |
| * @param __list A %forward_list of identical element and allocator |
| * types. |
| * |
| * The newly-created %forward_list contains the exact contents of the |
| * moved instance. The contents of the moved instance are a valid, but |
| * unspecified %forward_list. |
| */ |
| forward_list(forward_list&&) = default; |
| |
| /** |
| * @brief Builds a %forward_list from an initializer_list |
| * @param __il An initializer_list of value_type. |
| * @param __al An allocator object. |
| * |
| * Create a %forward_list consisting of copies of the elements |
| * in the initializer_list `__il`. This is linear in `__il.size()`. |
| */ |
| forward_list(std::initializer_list<_Tp> __il, |
| const _Alloc& __al = _Alloc()) |
| : _Base(_Node_alloc_type(__al)) |
| { _M_range_initialize(__il.begin(), __il.end()); } |
| |
| /** |
| * @brief The forward_list dtor. |
| */ |
| ~forward_list() noexcept |
| { } |
| |
| /** |
| * @brief The %forward_list assignment operator. |
| * @param __list A %forward_list of identical element and allocator |
| * types. |
| * |
| * All the elements of `__list` are copied. |
| * |
| * Whether the allocator is copied depends on the allocator traits. |
| */ |
| forward_list& |
| operator=(const forward_list& __list); |
| |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr |
| /** |
| * @brief The %forward_list move assignment operator. |
| * @param __list A %forward_list of identical element and allocator |
| * types. |
| * |
| * The contents of `__list` are moved into this %forward_list |
| * (without copying, if the allocators permit it). |
| * |
| * Afterwards @a __list is a valid, but unspecified %forward_list |
| * |
| * Whether the allocator is moved depends on the allocator traits. |
| */ |
| forward_list& |
| operator=(forward_list&& __list) |
| noexcept(_Node_alloc_traits::_S_nothrow_move()) |
| { |
| constexpr bool __move_storage = |
| _Node_alloc_traits::_S_propagate_on_move_assign() |
| || _Node_alloc_traits::_S_always_equal(); |
| if constexpr (!__move_storage) |
| { |
| if (__list._M_get_Node_allocator() != this->_M_get_Node_allocator()) |
| { |
| // The rvalue's allocator cannot be moved, or is not equal, |
| // so we need to individually move each element. |
| this->assign(std::make_move_iterator(__list.begin()), |
| std::make_move_iterator(__list.end())); |
| return *this; |
| } |
| } |
| |
| clear(); |
| this->_M_impl._M_head._M_next = __list._M_impl._M_head._M_next; |
| __list._M_impl._M_head._M_next = nullptr; |
| if constexpr (_Node_alloc_traits::_S_propagate_on_move_assign()) |
| this->_M_get_Node_allocator() |
| = std::move(__list._M_get_Node_allocator()); |
| return *this; |
| } |
| |
| /** |
| * @brief The %forward_list initializer list assignment operator. |
| * @param __il An initializer_list of value_type. |
| * |
| * Replace the contents of the %forward_list with copies of the |
| * elements in the initializer_list `__il`. This is linear in |
| * `__il.size()`. |
| */ |
| forward_list& |
| operator=(std::initializer_list<_Tp> __il) |
| { |
| assign(__il); |
| return *this; |
| } |
| |
| /** |
| * @brief Assigns a range to a %forward_list. |
| * @param __first An input iterator. |
| * @param __last An input iterator. |
| * |
| * This function fills a %forward_list with copies of the elements |
| * in the range `[ __first,__last)`. |
| * |
| * Note that the assignment completely changes the %forward_list and |
| * that the number of elements of the resulting %forward_list is the |
| * same as the number of elements assigned. |
| */ |
| template<typename _InputIterator, |
| typename = std::_RequireInputIter<_InputIterator>> |
| void |
| assign(_InputIterator __first, _InputIterator __last) |
| { |
| if constexpr (is_assignable<_Tp, decltype(*__first)>::value) |
| { |
| auto __prev = before_begin(); |
| auto __curr = begin(); |
| auto __end = end(); |
| while (__curr != __end && __first != __last) |
| { |
| *__curr = *__first; |
| ++__prev; |
| ++__curr; |
| ++__first; |
| } |
| if (__first != __last) |
| insert_after(__prev, __first, __last); |
| else if (__curr != __end) |
| erase_after(__prev, __end); |
| } |
| else |
| { |
| clear(); |
| insert_after(cbefore_begin(), __first, __last); |
| } |
| } |
| #pragma GCC diagnostic pop |
| |
| #if __glibcxx_containers_ranges // C++ >= 23 |
| /** |
| * @brief Assign a range to a forward_list. |
| * @since C++23 |
| */ |
| template<__detail::__container_compatible_range<_Tp> _Rg> |
| void |
| assign_range(_Rg&& __rg) |
| { |
| static_assert(assignable_from<_Tp&, ranges::range_reference_t<_Rg>>); |
| |
| auto __first = ranges::begin(__rg); |
| const auto __last = ranges::end(__rg); |
| iterator __prev = before_begin(); |
| iterator __curr = begin(); |
| const iterator __end = end(); |
| |
| while (__curr != __end && __first != __last) |
| { |
| *__curr = *__first; |
| __prev = __curr; |
| ++__first; |
| ++__curr; |
| } |
| |
| if (__curr != __end) |
| erase_after(__prev, __end); |
| else |
| insert_range_after(__prev, |
| ranges::subrange(std::move(__first), __last)); |
| } |
| #endif // containers_ranges |
| |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr |
| /** |
| * @brief Assigns a given value to a %forward_list. |
| * @param __n Number of elements to be assigned. |
| * @param __val Value to be assigned. |
| * |
| * This function fills a %forward_list with `__n` copies of the |
| * given value. Note that the assignment completely changes the |
| * %forward_list, and that the resulting %forward_list has `__n` |
| * elements. |
| */ |
| void |
| assign(size_type __n, const _Tp& __val) |
| { |
| if constexpr (is_copy_assignable<_Tp>::value) |
| { |
| auto __prev = before_begin(); |
| auto __curr = begin(); |
| auto __end = end(); |
| while (__curr != __end && __n > 0) |
| { |
| *__curr = __val; |
| ++__prev; |
| ++__curr; |
| --__n; |
| } |
| if (__n > 0) |
| insert_after(__prev, __n, __val); |
| else if (__curr != __end) |
| erase_after(__prev, __end); |
| } |
| else |
| { |
| clear(); |
| insert_after(cbefore_begin(), __n, __val); |
| } |
| } |
| #pragma GCC diagnostic pop |
| |
| /** |
| * @brief Assigns an initializer_list to a %forward_list. |
| * @param __il An initializer_list of value_type. |
| * |
| * Replace the contents of the %forward_list with copies of the |
| * elements in the initializer_list `__il`. This is linear in |
| * `__il.size()`. |
| */ |
| void |
| assign(std::initializer_list<_Tp> __il) |
| { assign(__il.begin(), __il.end()); } |
| |
| /// Get a copy of the memory allocation object. |
| allocator_type |
| get_allocator() const noexcept |
| { return allocator_type(this->_M_get_Node_allocator()); } |
| |
| // 23.3.4.3 iterators: |
| |
| /** |
| * Returns a read/write iterator that points before the first element |
| * in the %forward_list. Iteration is done in ordinary element order. |
| */ |
| [[__nodiscard__]] |
| iterator |
| before_begin() noexcept |
| { return iterator(this->_M_impl._M_head._M_base_ptr()); } |
| |
| /** |
| * Returns a read-only (constant) iterator that points before the |
| * first element in the %forward_list. Iteration is done in ordinary |
| * element order. |
| */ |
| [[__nodiscard__]] |
| const_iterator |
| before_begin() const noexcept |
| { return const_iterator(this->_M_impl._M_head._M_base_ptr()); } |
| |
| /** |
| * Returns a read/write iterator that points to the first element |
| * in the %forward_list. Iteration is done in ordinary element order. |
| */ |
| [[__nodiscard__]] |
| iterator |
| begin() noexcept |
| { return iterator(this->_M_impl._M_head._M_next); } |
| |
| /** |
| * Returns a read-only (constant) iterator that points to the first |
| * element in the %forward_list. Iteration is done in ordinary |
| * element order. |
| */ |
| [[__nodiscard__]] |
| const_iterator |
| begin() const noexcept |
| { return const_iterator(this->_M_impl._M_head._M_next); } |
| |
| /** |
| * Returns a read/write iterator that points one past the last |
| * element in the %forward_list. Iteration is done in ordinary |
| * element order. |
| */ |
| [[__nodiscard__]] |
| iterator |
| end() noexcept |
| { return iterator(nullptr); } |
| |
| /** |
| * Returns a read-only iterator that points one past the last |
| * element in the %forward_list. Iteration is done in ordinary |
| * element order. |
| */ |
| [[__nodiscard__]] |
| const_iterator |
| end() const noexcept |
| { return const_iterator(nullptr); } |
| |
| /** |
| * Returns a read-only (constant) iterator that points to the |
| * first element in the %forward_list. Iteration is done in ordinary |
| * element order. |
| */ |
| [[__nodiscard__]] |
| const_iterator |
| cbegin() const noexcept |
| { return const_iterator(this->_M_impl._M_head._M_next); } |
| |
| /** |
| * Returns a read-only (constant) iterator that points before the |
| * first element in the %forward_list. Iteration is done in ordinary |
| * element order. |
| */ |
| [[__nodiscard__]] |
| const_iterator |
| cbefore_begin() const noexcept |
| { return const_iterator(this->_M_impl._M_head._M_base_ptr()); } |
| |
| /** |
| * Returns a read-only (constant) iterator that points one past |
| * the last element in the %forward_list. Iteration is done in |
| * ordinary element order. |
| */ |
| [[__nodiscard__]] |
| const_iterator |
| cend() const noexcept |
| { return const_iterator(nullptr); } |
| |
| /** |
| * Returns true if the %forward_list is empty. (Thus begin() would |
| * equal end().) |
| */ |
| [[__nodiscard__]] |
| bool |
| empty() const noexcept |
| { return this->_M_impl._M_head._M_next == nullptr; } |
| |
| /** |
| * Returns the largest possible number of elements of %forward_list. |
| */ |
| [[__nodiscard__]] |
| size_type |
| max_size() const noexcept |
| { return _Node_alloc_traits::max_size(this->_M_get_Node_allocator()); } |
| |
| // 23.3.4.4 element access: |
| |
| /** |
| * Returns a read/write reference to the data at the first |
| * element of the %forward_list. |
| */ |
| [[__nodiscard__]] |
| reference |
| front() |
| { |
| __glibcxx_requires_nonempty(); |
| _Node& __front = static_cast<_Node&>(*this->_M_impl._M_head._M_next); |
| return *__front._M_valptr(); |
| } |
| |
| /** |
| * Returns a read-only (constant) reference to the data at the first |
| * element of the %forward_list. |
| */ |
| [[__nodiscard__]] |
| const_reference |
| front() const |
| { |
| __glibcxx_requires_nonempty(); |
| _Node& __front = static_cast<_Node&>(*this->_M_impl._M_head._M_next); |
| return *__front._M_valptr(); |
| } |
| |
| // 23.3.4.5 modifiers: |
| |
| /** |
| * @brief Constructs object in %forward_list at the front of the |
| * list. |
| * @param __args Arguments. |
| * |
| * This function will insert an object of type `Tp` constructed |
| * with `Tp(std::forward<Args>(args)...)` at the front of the list |
| * Due to the nature of a %forward_list this operation can |
| * be done in constant time, and does not invalidate iterators |
| * and references. |
| */ |
| template<typename... _Args> |
| #if __cplusplus > 201402L |
| reference |
| #else |
| void |
| #endif |
| emplace_front(_Args&&... __args) |
| { |
| this->_M_insert_after(cbefore_begin(), |
| std::forward<_Args>(__args)...); |
| #if __cplusplus > 201402L |
| return front(); |
| #endif |
| } |
| |
| /** |
| * @brief Add data to the front of the %forward_list. |
| * @param __val Data to be added. |
| * |
| * This is a typical stack operation. The function creates an |
| * element at the front of the %forward_list and assigns the given |
| * data to it. Due to the nature of a %forward_list this operation |
| * can be done in constant time, and does not invalidate iterators |
| * and references. |
| */ |
| void |
| push_front(const _Tp& __val) |
| { this->_M_insert_after(cbefore_begin(), __val); } |
| |
| /** |
| * |
| */ |
| void |
| push_front(_Tp&& __val) |
| { this->_M_insert_after(cbefore_begin(), std::move(__val)); } |
| |
| #if __glibcxx_containers_ranges // C++ >= 23 |
| /** |
| * @brief Insert a range at the beginning of a forward_list. |
| * @param __rg An input range with elements that are convertible to |
| * the forward_list's value_type. |
| * |
| * The inserted elements will be in the same order as in the range, |
| * so they are not reversed as would happen with a simple loop calling |
| * `emplace_front` for each element of the range. |
| * |
| * No iterators to existing elements are invalidated by this function. |
| * If the insertion fails due to an exception, no elements will be added |
| * and so the list will be unchanged. |
| * |
| * @since C++23 |
| */ |
| template<__detail::__container_compatible_range<_Tp> _Rg> |
| void |
| prepend_range(_Rg&& __rg) |
| { |
| forward_list __tmp(from_range, std::forward<_Rg>(__rg), |
| get_allocator()); |
| if (!__tmp.empty()) |
| splice_after(before_begin(), __tmp); |
| } |
| #endif // containers_ranges |
| |
| /** |
| * @brief Removes first element. |
| * |
| * This is a typical stack operation. It shrinks the %forward_list |
| * by one. Due to the nature of a %forward_list this operation can |
| * be done in constant time, and only invalidates iterators/references |
| * to the element being removed. |
| * |
| * Note that no data is returned, and if the first element's data |
| * is needed, it should be retrieved before `pop_front()` is |
| * called. |
| */ |
| void |
| pop_front() |
| { |
| __glibcxx_requires_nonempty(); |
| this->_M_erase_after(this->_M_impl._M_head._M_base_ptr()); |
| } |
| |
| /** |
| * @brief Constructs object in %forward_list after the specified |
| * iterator. |
| * @param __pos A const_iterator into the %forward_list. |
| * @param __args Arguments. |
| * @return An iterator that points to the inserted data. |
| * |
| * This function will insert an object of type `T` constructed |
| * with `T(std::forward<Args>(args)...)` after the specified |
| * location. Due to the nature of a %forward_list this operation can |
| * be done in constant time, and does not invalidate iterators |
| * and references. |
| */ |
| template<typename... _Args> |
| iterator |
| emplace_after(const_iterator __pos, _Args&&... __args) |
| { return iterator(this->_M_insert_after(__pos, |
| std::forward<_Args>(__args)...)); } |
| |
| /** |
| * @brief Inserts given value into %forward_list after specified |
| * iterator. |
| * @param __pos An iterator into the %forward_list. |
| * @param __val Data to be inserted. |
| * @return An iterator that points to the inserted data. |
| * |
| * This function will insert a copy of the given value after |
| * the specified location. Due to the nature of a %forward_list this |
| * operation can be done in constant time, and does not |
| * invalidate iterators and references. |
| */ |
| iterator |
| insert_after(const_iterator __pos, const _Tp& __val) |
| { return iterator(this->_M_insert_after(__pos, __val)); } |
| |
| /** |
| * |
| */ |
| iterator |
| insert_after(const_iterator __pos, _Tp&& __val) |
| { return iterator(this->_M_insert_after(__pos, std::move(__val))); } |
| |
| /** |
| * @brief Inserts a number of copies of given data into the |
| * %forward_list. |
| * @param __pos An iterator into the %forward_list. |
| * @param __n Number of elements to be inserted. |
| * @param __val Data to be inserted. |
| * @return An iterator pointing to the last inserted copy of |
| * `val` or `pos` if `n == 0`. |
| * |
| * This function will insert a specified number of copies of the |
| * given data after the location specified by `pos`. |
| * |
| * This operation is linear in the number of elements inserted and |
| * does not invalidate iterators and references. |
| */ |
| iterator |
| insert_after(const_iterator __pos, size_type __n, const _Tp& __val); |
| |
| /** |
| * @brief Inserts a range into the %forward_list. |
| * @param __pos An iterator into the %forward_list. |
| * @param __first An input iterator. |
| * @param __last An input iterator. |
| * @return An iterator pointing to the last inserted element or |
| * `__pos` if `__first == __last`. |
| * |
| * This function will insert copies of the data in the range |
| * `[ __first, __last)` into the %forward_list after the |
| * location specified by `__pos. |
| * |
| * This operation is linear in the number of elements inserted and |
| * does not invalidate iterators and references. |
| */ |
| template<typename _InputIterator, |
| typename = std::_RequireInputIter<_InputIterator>> |
| iterator |
| insert_after(const_iterator __pos, |
| _InputIterator __first, _InputIterator __last); |
| |
| /** |
| * @brief Inserts the contents of an initializer_list into |
| * %forward_list after the specified iterator. |
| * @param __pos An iterator into the %forward_list. |
| * @param __il An initializer_list of value_type. |
| * @return An iterator pointing to the last inserted element |
| * or `__pos` if `__il` is empty. |
| * |
| * This function will insert copies of the data in the |
| * initializer_list `__il` into the %forward_list before the location |
| * specified by `__pos`. |
| * |
| * This operation is linear in the number of elements inserted and |
| * does not invalidate iterators and references. |
| */ |
| iterator |
| insert_after(const_iterator __pos, std::initializer_list<_Tp> __il) |
| { return insert_after(__pos, __il.begin(), __il.end()); } |
| |
| #if __glibcxx_containers_ranges // C++ >= 23 |
| /** |
| * @brief Insert a rangeinto a forward_list. |
| * @param __position An iterator. |
| * @param __rg An input range of elements that can be converted to |
| * the forward_list's value type. |
| * @return An iterator pointing to the last element inserted, |
| * or `__position` if the range is empty. |
| * |
| * Inserts the elements of `__rg` after `__position`. |
| * No iterators to existing elements are invalidated by this function. |
| * If the insertion fails due to an exception, no elements will be added |
| * and so the list will be unchanged. |
| * |
| * @since C++23 |
| */ |
| template<__detail::__container_compatible_range<_Tp> _Rg> |
| iterator |
| insert_range_after(const_iterator __position, _Rg&& __rg) |
| { |
| forward_list __tmp(from_range, std::forward<_Rg>(__rg), |
| get_allocator()); |
| return _M_splice_after(__position, __tmp.before_begin(), __tmp.end()); |
| } |
| #endif // containers_ranges |
| |
| /** |
| * @brief Removes the element pointed to by the iterator following |
| * `pos`. |
| * @param __pos Iterator pointing before element to be erased. |
| * @return An iterator pointing to the element following the one |
| * that was erased, or `end()` if no such element exists. |
| * |
| * This function will erase the element at the given position and |
| * thus shorten the %forward_list by one. |
| * |
| * Due to the nature of a %forward_list this operation can be done |
| * in constant time, and only invalidates iterators/references to |
| * the element being removed. The user is also cautioned that |
| * this function only erases the element, and that if the element |
| * is itself a pointer, the pointed-to memory is not touched in |
| * any way. Managing the pointer is the user's responsibility. |
| */ |
| iterator |
| erase_after(const_iterator __pos) |
| { return iterator(this->_M_erase_after(__pos._M_const_cast()._M_node)); } |
| |
| /** |
| * @brief Remove a range of elements. |
| * @param __pos Iterator pointing before the first element to be |
| * erased. |
| * @param __last Iterator pointing to one past the last element to be |
| * erased. |
| * @return `__last` |
| * |
| * This function will erase the elements in the range |
| * `(__pos,__last)` and shorten the %forward_list accordingly. |
| * |
| * This operation is linear time in the size of the range and only |
| * invalidates iterators/references to the element being removed. |
| * |
| * The user is also cautioned that this function only erases the |
| * elements, and that if the elements themselves are pointers, the |
| * pointed-to memory is not touched in any way. Managing the pointer |
| * is the user's responsibility. |
| */ |
| iterator |
| erase_after(const_iterator __pos, const_iterator __last) |
| { |
| return iterator(this->_M_erase_after(__pos._M_const_cast()._M_node, |
| __last._M_const_cast()._M_node)); |
| } |
| |
| /** |
| * @brief Swaps data with another %forward_list. |
| * @param __list A %forward_list of the same element and allocator |
| * types. |
| * |
| * This exchanges the elements between two lists in constant |
| * time. Note that the global `std::swap()` function is |
| * overloaded such that `std::swap(l1, l2)` will feed to this |
| * function. |
| * |
| * Whether the allocators are swapped depends on the allocator traits. |
| */ |
| void |
| swap(forward_list& __list) noexcept |
| { |
| std::swap(this->_M_impl._M_head._M_next, |
| __list._M_impl._M_head._M_next); |
| _Node_alloc_traits::_S_on_swap(this->_M_get_Node_allocator(), |
| __list._M_get_Node_allocator()); |
| } |
| |
| /** |
| * @brief Resizes the %forward_list to the specified number of |
| * elements. |
| * @param __sz Number of elements the %forward_list should contain. |
| * |
| * This function will %resize the %forward_list to the specified |
| * number of elements. If the number is smaller than the |
| * %forward_list's current number of elements the %forward_list |
| * is truncated, otherwise the %forward_list is extended and the |
| * new elements are default constructed. |
| */ |
| void |
| resize(size_type __sz); |
| |
| /** |
| * @brief Resizes the %forward_list to the specified number of |
| * elements. |
| * @param __sz Number of elements the %forward_list should contain. |
| * @param __val Data with which new elements should be populated. |
| * |
| * This function will %resize the %forward_list to the specified |
| * number of elements. If the number is smaller than the |
| * %forward_list's current number of elements the %forward_list |
| * is truncated, otherwise the %forward_list is extended and new |
| * elements are populated with given data. |
| */ |
| void |
| resize(size_type __sz, const value_type& __val); |
| |
| /** |
| * @brief Erases all the elements. |
| * |
| * Note that this function only erases |
| * the elements, and that if the elements themselves are |
| * pointers, the pointed-to memory is not touched in any way. |
| * Managing the pointer is the user's responsibility. |
| */ |
| void |
| clear() noexcept |
| { this->_M_erase_after(this->_M_impl._M_head._M_base_ptr(), nullptr); } |
| |
| // 23.3.4.6 forward_list operations: |
| |
| /** |
| * @brief Insert contents of another %forward_list. |
| * @param __pos Iterator referencing the element to insert after. |
| * @param __list Source list. |
| * |
| * The elements of `list` are inserted in constant time after |
| * the element referenced by `pos`. `list` becomes an empty |
| * list. |
| * |
| * Requires `this != &x`. |
| */ |
| void |
| splice_after(const_iterator __pos, forward_list&& __list) noexcept |
| { |
| if (!__list.empty()) |
| _M_splice_after(__pos, __list.before_begin(), __list.end()); |
| } |
| |
| void |
| splice_after(const_iterator __pos, forward_list& __list) noexcept |
| { splice_after(__pos, std::move(__list)); } |
| |
| /** |
| * @brief Insert element from another %forward_list. |
| * @param __pos Iterator referencing the element to insert after. |
| * @param __list Source list. |
| * @param __i Iterator referencing the element before the element |
| * to move. |
| * |
| * Removes the element in list `__list` referenced by `__i` and |
| * inserts it into the current list after `__pos`. |
| */ |
| void |
| splice_after(const_iterator __pos, forward_list&& __list, |
| const_iterator __i) noexcept; |
| |
| void |
| splice_after(const_iterator __pos, forward_list& __list, |
| const_iterator __i) noexcept |
| { splice_after(__pos, std::move(__list), __i); } |
| |
| /** |
| * @brief Insert range from another %forward_list. |
| * @param __pos Iterator referencing the element to insert after. |
| * @param __list Source list. |
| * @param __before Iterator referencing before the start of range |
| * in `__list`. |
| * @param __last Iterator referencing the end of range in `__list`. |
| * |
| * Removes elements in the range `(__before,__last)` and inserts them |
| * after `__pos` in constant time. |
| * |
| * Undefined if `__pos` is in `(__before,__last)`. |
| * @{ |
| */ |
| void |
| splice_after(const_iterator __pos, forward_list&&, |
| const_iterator __before, const_iterator __last) noexcept |
| { _M_splice_after(__pos, __before, __last); } |
| |
| void |
| splice_after(const_iterator __pos, forward_list&, |
| const_iterator __before, const_iterator __last) noexcept |
| { _M_splice_after(__pos, __before, __last); } |
| /// @} |
| |
| private: |
| #ifdef __glibcxx_list_remove_return_type // C++20 && HOSTED |
| using __remove_return_type = size_type; |
| # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG \ |
| __attribute__((__abi_tag__("__cxx20"))) |
| #else |
| using __remove_return_type = void; |
| # define _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG |
| #endif |
| public: |
| |
| /** |
| * @brief Remove all elements equal to value. |
| * @param __val The value to remove. |
| * |
| * Removes every element in the list equal to `__val`. |
| * Remaining elements stay in list order. Note that this |
| * function only erases the elements, and that if the elements |
| * themselves are pointers, the pointed-to memory is not |
| * touched in any way. Managing the pointer is the user's |
| * responsibility. |
| */ |
| _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG |
| __remove_return_type |
| remove(const _Tp& __val); |
| |
| /** |
| * @brief Remove all elements satisfying a predicate. |
| * @param __pred Unary predicate function or object. |
| * |
| * Removes every element in the list for which the predicate |
| * returns true. Remaining elements stay in list order. Note |
| * that this function only erases the elements, and that if the |
| * elements themselves are pointers, the pointed-to memory is |
| * not touched in any way. Managing the pointer is the user's |
| * responsibility. |
| */ |
| template<typename _Pred> |
| __remove_return_type |
| remove_if(_Pred __pred); |
| |
| /** |
| * @brief Remove consecutive duplicate elements. |
| * |
| * For each consecutive set of elements with the same value, |
| * remove all but the first one. Remaining elements stay in |
| * list order. Note that this function only erases the |
| * elements, and that if the elements themselves are pointers, |
| * the pointed-to memory is not touched in any way. Managing |
| * the pointer is the user's responsibility. |
| */ |
| _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG |
| __remove_return_type |
| unique() |
| { return unique(std::equal_to<_Tp>()); } |
| |
| #undef _GLIBCXX_FWDLIST_REMOVE_RETURN_TYPE_TAG |
| |
| /** |
| * @brief Remove consecutive elements satisfying a predicate. |
| * @param __binary_pred Binary predicate function or object. |
| * |
| * For each consecutive set of elements [first,last) that |
| * satisfy predicate(first,i) where i is an iterator in |
| * [first,last), remove all but the first one. Remaining |
| * elements stay in list order. Note that this function only |
| * erases the elements, and that if the elements themselves are |
| * pointers, the pointed-to memory is not touched in any way. |
| * Managing the pointer is the user's responsibility. |
| */ |
| template<typename _BinPred> |
| __remove_return_type |
| unique(_BinPred __binary_pred); |
| |
| /** |
| * @brief Merge sorted lists. |
| * @param __list Sorted list to merge. |
| * |
| * Assumes that both `__list` and this list are sorted according to |
| * operator<(). Merges elements of `__list` into this list in |
| * sorted order, leaving `__list` empty when complete. Elements in |
| * this list precede elements in `__list` that are equal. |
| */ |
| void |
| merge(forward_list&& __list) |
| { merge(std::move(__list), std::less<_Tp>()); } |
| |
| void |
| merge(forward_list& __list) |
| { merge(std::move(__list)); } |
| |
| /** |
| * @brief Merge sorted lists according to comparison function. |
| * @param __list Sorted list to merge. |
| * @param __comp Comparison function defining sort order. |
| * |
| * Assumes that both `__list` and this list are sorted according to |
| * comp. Merges elements of `__list` into this list |
| * in sorted order, leaving `__list` empty when complete. Elements |
| * in this list precede elements in `__list` that are equivalent |
| * according to comp(). |
| */ |
| template<typename _Comp> |
| void |
| merge(forward_list&& __list, _Comp __comp); |
| |
| template<typename _Comp> |
| void |
| merge(forward_list& __list, _Comp __comp) |
| { merge(std::move(__list), __comp); } |
| |
| /** |
| * @brief Sort the elements of the list. |
| * |
| * Sorts the elements of this list in NlogN time. Equivalent |
| * elements remain in list order. |
| */ |
| void |
| sort() |
| { sort(std::less<_Tp>()); } |
| |
| /** |
| * @brief Sort the forward_list using a comparison function. |
| * |
| * Sorts the elements of this list in NlogN time. Equivalent |
| * elements remain in list order. |
| */ |
| template<typename _Comp> |
| void |
| sort(_Comp __comp); |
| |
| /** |
| * @brief Reverse the elements in list. |
| * |
| * Reverse the order of elements in the list in linear time. |
| */ |
| void |
| reverse() noexcept |
| { this->_M_impl._M_head._M_reverse_after(); } |
| |
| private: |
| // Called by the range constructor to implement [23.3.4.2]/9 |
| template<typename _InputIterator> |
| void |
| _M_range_initialize(_InputIterator __first, _InputIterator __last); |
| |
| // Called by forward_list(n,v,a), and the range constructor when it |
| // turns out to be the same thing. |
| void |
| _M_fill_initialize(size_type __n, const value_type& __value); |
| |
| // Called by splice_after and insert_after. |
| iterator |
| _M_splice_after(const_iterator __pos, const_iterator __before, |
| const_iterator __last); |
| |
| // Called by forward_list(n). |
| void |
| _M_default_initialize(size_type __n); |
| |
| // Called by resize(sz). |
| void |
| _M_default_insert_after(const_iterator __pos, size_type __n); |
| |
| #if ! _GLIBCXX_INLINE_VERSION |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wc++17-extensions" // if constexpr |
| // XXX GLIBCXX_ABI Deprecated |
| // These members are unused by std::forward_list now, but we keep them |
| // here so that an explicit instantiation will define them. |
| // This ensures that explicit instantiations still define these symbols, |
| // so that explicit instantiation declarations of std::forward_list that |
| // were compiled with old versions of GCC can still find these symbols. |
| |
| // Use 'if constexpr' so that the functions don't do anything for |
| // specializations using _Node_traits<T, fancy-pointer>, because any |
| // old code referencing these symbols wasn't using the fancy-pointer |
| // specializations. |
| |
| void |
| _M_move_assign(forward_list&& __list, true_type) noexcept |
| { |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| if constexpr (is_same<typename _Alloc_traits::pointer, _Tp*>::value) |
| #endif |
| { |
| clear(); |
| this->_M_impl._M_head._M_next = __list._M_impl._M_head._M_next; |
| __list._M_impl._M_head._M_next = nullptr; |
| std::__alloc_on_move(this->_M_get_Node_allocator(), |
| __list._M_get_Node_allocator()); |
| } |
| } |
| |
| void |
| _M_move_assign(forward_list&& __list, false_type) |
| { |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| if constexpr (is_same<typename _Alloc_traits::pointer, _Tp*>::value) |
| #endif |
| { |
| if (__list._M_get_Node_allocator() == this->_M_get_Node_allocator()) |
| _M_move_assign(std::move(__list), true_type()); |
| else |
| // The rvalue's allocator cannot be moved, or is not equal, |
| // so we need to individually move each element. |
| this->assign(std::make_move_iterator(__list.begin()), |
| std::make_move_iterator(__list.end())); |
| } |
| } |
| |
| void |
| _M_assign_n(size_type __n, const _Tp& __val, true_type) |
| { |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| if constexpr (is_same<typename _Alloc_traits::pointer, _Tp*>::value) |
| #endif |
| { |
| auto __prev = before_begin(); |
| auto __curr = begin(); |
| auto __end = end(); |
| while (__curr != __end && __n > 0) |
| { |
| *__curr = __val; |
| ++__prev; |
| ++__curr; |
| --__n; |
| } |
| if (__n > 0) |
| insert_after(__prev, __n, __val); |
| else if (__curr != __end) |
| erase_after(__prev, __end); |
| } |
| } |
| |
| void |
| _M_assign_n(size_type __n, const _Tp& __val, false_type) |
| { |
| #if _GLIBCXX_USE_ALLOC_PTR_FOR_FWD_LIST |
| if constexpr (is_same<typename _Alloc_traits::pointer, _Tp*>::value) |
| #endif |
| { |
| clear(); |
| insert_after(cbefore_begin(), __n, __val); |
| } |
| } |
| #pragma GCC diagnostic pop |
| #endif // ! _GLIBCXX_INLINE_VERSION |
| }; |
| |
| #if __cpp_deduction_guides >= 201606 |
| template<typename _InputIterator, typename _ValT |
| = typename iterator_traits<_InputIterator>::value_type, |
| typename _Allocator = allocator<_ValT>, |
| typename = _RequireInputIter<_InputIterator>, |
| typename = _RequireAllocator<_Allocator>> |
| forward_list(_InputIterator, _InputIterator, _Allocator = _Allocator()) |
| -> forward_list<_ValT, _Allocator>; |
| |
| #if __glibcxx_containers_ranges // C++ >= 23 |
| template<ranges::input_range _Rg, |
| typename _Allocator = allocator<ranges::range_value_t<_Rg>>> |
| forward_list(from_range_t, _Rg&&, _Allocator = _Allocator()) |
| -> forward_list<ranges::range_value_t<_Rg>, _Allocator>; |
| #endif |
| #endif |
| |
| /** |
| * @brief Forward list equality comparison. |
| * @param __lx A %forward_list |
| * @param __ly A %forward_list of the same type as `__lx`. |
| * @return True iff the elements of the forward lists are equal. |
| * |
| * This is an equivalence relation. It is linear in the number of |
| * elements of the forward lists. Deques are considered equivalent |
| * if corresponding elements compare equal. |
| */ |
| template<typename _Tp, typename _Alloc> |
| [[__nodiscard__]] |
| bool |
| operator==(const forward_list<_Tp, _Alloc>& __lx, |
| const forward_list<_Tp, _Alloc>& __ly); |
| |
| #if __cpp_lib_three_way_comparison |
| /** |
| * @brief Forward list ordering relation. |
| * @param __x A `forward_list`. |
| * @param __y A `forward_list` of the same type as `__x`. |
| * @return A value indicating whether `__x` is less than, equal to, |
| * greater than, or incomparable with `__y`. |
| * |
| * See `std::lexicographical_compare_three_way()` for how the determination |
| * is made. This operator is used to synthesize relational operators like |
| * `<` and `>=` etc. |
| */ |
| template<typename _Tp, typename _Alloc> |
| [[nodiscard]] |
| inline __detail::__synth3way_t<_Tp> |
| operator<=>(const forward_list<_Tp, _Alloc>& __x, |
| const forward_list<_Tp, _Alloc>& __y) |
| { |
| return std::lexicographical_compare_three_way(__x.begin(), __x.end(), |
| __y.begin(), __y.end(), |
| __detail::__synth3way); |
| } |
| #else |
| /** |
| * @brief Forward list ordering relation. |
| * @param __lx A %forward_list. |
| * @param __ly A %forward_list of the same type as `__lx`. |
| * @return True iff `__lx` is lexicographically less than `__ly`. |
| * |
| * This is a total ordering relation. It is linear in the number of |
| * elements of the forward lists. The elements must be comparable |
| * with `<`. |
| * |
| * See std::lexicographical_compare() for how the determination is made. |
| */ |
| template<typename _Tp, typename _Alloc> |
| [[__nodiscard__]] |
| inline bool |
| operator<(const forward_list<_Tp, _Alloc>& __lx, |
| const forward_list<_Tp, _Alloc>& __ly) |
| { return std::lexicographical_compare(__lx.cbegin(), __lx.cend(), |
| __ly.cbegin(), __ly.cend()); } |
| |
| /// Based on operator== |
| template<typename _Tp, typename _Alloc> |
| [[__nodiscard__]] |
| inline bool |
| operator!=(const forward_list<_Tp, _Alloc>& __lx, |
| const forward_list<_Tp, _Alloc>& __ly) |
| { return !(__lx == __ly); } |
| |
| /// Based on operator< |
| template<typename _Tp, typename _Alloc> |
| [[__nodiscard__]] |
| inline bool |
| operator>(const forward_list<_Tp, _Alloc>& __lx, |
| const forward_list<_Tp, _Alloc>& __ly) |
| { return (__ly < __lx); } |
| |
| /// Based on operator< |
| template<typename _Tp, typename _Alloc> |
| [[__nodiscard__]] |
| inline bool |
| operator>=(const forward_list<_Tp, _Alloc>& __lx, |
| const forward_list<_Tp, _Alloc>& __ly) |
| { return !(__lx < __ly); } |
| |
| /// Based on operator< |
| template<typename _Tp, typename _Alloc> |
| [[__nodiscard__]] |
| inline bool |
| operator<=(const forward_list<_Tp, _Alloc>& __lx, |
| const forward_list<_Tp, _Alloc>& __ly) |
| { return !(__ly < __lx); } |
| #endif // three-way comparison |
| |
| /// See std::forward_list::swap(). |
| template<typename _Tp, typename _Alloc> |
| inline void |
| swap(forward_list<_Tp, _Alloc>& __lx, |
| forward_list<_Tp, _Alloc>& __ly) |
| noexcept(noexcept(__lx.swap(__ly))) |
| { __lx.swap(__ly); } |
| |
| _GLIBCXX_END_NAMESPACE_CONTAINER |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace std |
| |
| #endif // _FORWARD_LIST_H |
