// Stack implementation -*- C++ -*- // Copyright (C) 2001-2020 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/>. /* * * Copyright (c) 1994 * Hewlett-Packard Company * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Hewlett-Packard Company makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * * * Copyright (c) 1996,1997 * Silicon Graphics Computer Systems, Inc. * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Silicon Graphics makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. */ /** @file bits/stl_stack.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{stack} */ #ifndef _STL_STACK_H #define _STL_STACK_H 1 #include <bits/concept_check.h> #include <debug/debug.h> #if __cplusplus >= 201103L # include <bits/uses_allocator.h> #endif namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @brief A standard container giving FILO behavior. * * @ingroup sequences * * @tparam _Tp Type of element. * @tparam _Sequence Type of underlying sequence, defaults to deque<_Tp>. * * Meets many of the requirements of a * <a href="tables.html#65">container</a>, * but does not define anything to do with iterators. Very few of the * other standard container interfaces are defined. * * This is not a true container, but an @e adaptor. It holds * another container, and provides a wrapper interface to that * container. The wrapper is what enforces strict * first-in-last-out %stack behavior. * * The second template parameter defines the type of the underlying * sequence/container. It defaults to std::deque, but it can be * any type that supports @c back, @c push_back, and @c pop_back, * such as std::list, std::vector, or an appropriate user-defined * type. * * Members not found in @a normal containers are @c container_type, * which is a typedef for the second Sequence parameter, and @c * push, @c pop, and @c top, which are standard %stack/FILO * operations. */ template<typename _Tp, typename _Sequence = deque<_Tp> > class stack { #ifdef _GLIBCXX_CONCEPT_CHECKS // concept requirements typedef typename _Sequence::value_type _Sequence_value_type; # if __cplusplus < 201103L __glibcxx_class_requires(_Tp, _SGIAssignableConcept) __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept) # endif __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept) #endif template<typename _Tp1, typename _Seq1> friend bool operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&); template<typename _Tp1, typename _Seq1> friend bool operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&); #if __cpp_lib_three_way_comparison template<typename _Tp1, three_way_comparable _Seq1> friend compare_three_way_result_t<_Seq1> operator<=>(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&); #endif #if __cplusplus >= 201103L template<typename _Alloc> using _Uses = typename enable_if<uses_allocator<_Sequence, _Alloc>::value>::type; #if __cplusplus >= 201703L // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2566. Requirements on the first template parameter of container // adaptors static_assert(is_same<_Tp, typename _Sequence::value_type>::value, "value_type must be the same as the underlying container"); #endif // C++17 #endif // C++11 public: typedef typename _Sequence::value_type value_type; typedef typename _Sequence::reference reference; typedef typename _Sequence::const_reference const_reference; typedef typename _Sequence::size_type size_type; typedef _Sequence container_type; protected: // See queue::c for notes on this name. _Sequence c; public: // XXX removed old def ctor, added def arg to this one to match 14882 /** * @brief Default constructor creates no elements. */ #if __cplusplus < 201103L explicit stack(const _Sequence& __c = _Sequence()) : c(__c) { } #else template<typename _Seq = _Sequence, typename _Requires = typename enable_if<is_default_constructible<_Seq>::value>::type> stack() : c() { } explicit stack(const _Sequence& __c) : c(__c) { } explicit stack(_Sequence&& __c) : c(std::move(__c)) { } template<typename _Alloc, typename _Requires = _Uses<_Alloc>> explicit stack(const _Alloc& __a) : c(__a) { } template<typename _Alloc, typename _Requires = _Uses<_Alloc>> stack(const _Sequence& __c, const _Alloc& __a) : c(__c, __a) { } template<typename _Alloc, typename _Requires = _Uses<_Alloc>> stack(_Sequence&& __c, const _Alloc& __a) : c(std::move(__c), __a) { } template<typename _Alloc, typename _Requires = _Uses<_Alloc>> stack(const stack& __q, const _Alloc& __a) : c(__q.c, __a) { } template<typename _Alloc, typename _Requires = _Uses<_Alloc>> stack(stack&& __q, const _Alloc& __a) : c(std::move(__q.c), __a) { } #endif /** * Returns true if the %stack is empty. */ _GLIBCXX_NODISCARD bool empty() const { return c.empty(); } /** Returns the number of elements in the %stack. */ size_type size() const { return c.size(); } /** * Returns a read/write reference to the data at the first * element of the %stack. */ reference top() { __glibcxx_requires_nonempty(); return c.back(); } /** * Returns a read-only (constant) reference to the data at the first * element of the %stack. */ const_reference top() const { __glibcxx_requires_nonempty(); return c.back(); } /** * @brief Add data to the top of the %stack. * @param __x Data to be added. * * This is a typical %stack operation. The function creates an * element at the top of the %stack and assigns the given data * to it. The time complexity of the operation depends on the * underlying sequence. */ void push(const value_type& __x) { c.push_back(__x); } #if __cplusplus >= 201103L void push(value_type&& __x) { c.push_back(std::move(__x)); } #if __cplusplus > 201402L template<typename... _Args> decltype(auto) emplace(_Args&&... __args) { return c.emplace_back(std::forward<_Args>(__args)...); } #else template<typename... _Args> void emplace(_Args&&... __args) { c.emplace_back(std::forward<_Args>(__args)...); } #endif #endif /** * @brief Removes first element. * * This is a typical %stack operation. It shrinks the %stack * by one. The time complexity of the operation depends on the * underlying sequence. * * Note that no data is returned, and if the first element's * data is needed, it should be retrieved before pop() is * called. */ void pop() { __glibcxx_requires_nonempty(); c.pop_back(); } #if __cplusplus >= 201103L void swap(stack& __s) #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 noexcept(__is_nothrow_swappable<_Sequence>::value) #else noexcept(__is_nothrow_swappable<_Tp>::value) #endif { using std::swap; swap(c, __s.c); } #endif // __cplusplus >= 201103L }; #if __cpp_deduction_guides >= 201606 template<typename _Container, typename = _RequireNotAllocator<_Container>> stack(_Container) -> stack<typename _Container::value_type, _Container>; template<typename _Container, typename _Allocator, typename = _RequireNotAllocator<_Container>, typename = _RequireAllocator<_Allocator>> stack(_Container, _Allocator) -> stack<typename _Container::value_type, _Container>; #endif /** * @brief Stack equality comparison. * @param __x A %stack. * @param __y A %stack of the same type as @a __x. * @return True iff the size and elements of the stacks are equal. * * This is an equivalence relation. Complexity and semantics * depend on the underlying sequence type, but the expected rules * are: this relation is linear in the size of the sequences, and * stacks are considered equivalent if their sequences compare * equal. */ template<typename _Tp, typename _Seq> inline bool operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return __x.c == __y.c; } /** * @brief Stack ordering relation. * @param __x A %stack. * @param __y A %stack of the same type as @a x. * @return True iff @a x is lexicographically less than @a __y. * * This is an total ordering relation. Complexity and semantics * depend on the underlying sequence type, but the expected rules * are: this relation is linear in the size of the sequences, the * elements must be comparable with @c <, and * std::lexicographical_compare() is usually used to make the * determination. */ template<typename _Tp, typename _Seq> inline bool operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return __x.c < __y.c; } /// Based on operator== template<typename _Tp, typename _Seq> inline bool operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return !(__x == __y); } /// Based on operator< template<typename _Tp, typename _Seq> inline bool operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return __y < __x; } /// Based on operator< template<typename _Tp, typename _Seq> inline bool operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return !(__y < __x); } /// Based on operator< template<typename _Tp, typename _Seq> inline bool operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return !(__x < __y); } #if __cpp_lib_three_way_comparison template<typename _Tp, three_way_comparable _Seq> inline compare_three_way_result_t<_Seq> operator<=>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) { return __x.c <=> __y.c; } #endif #if __cplusplus >= 201103L template<typename _Tp, typename _Seq> inline #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 // Constrained free swap overload, see p0185r1 typename enable_if<__is_swappable<_Seq>::value>::type #else void #endif swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y) noexcept(noexcept(__x.swap(__y))) { __x.swap(__y); } template<typename _Tp, typename _Seq, typename _Alloc> struct uses_allocator<stack<_Tp, _Seq>, _Alloc> : public uses_allocator<_Seq, _Alloc>::type { }; #endif // __cplusplus >= 201103L _GLIBCXX_END_NAMESPACE_VERSION } // namespace #endif /* _STL_STACK_H */