11.2.0/bits/stl_stack.h

// Stack implementation -*- C++ -*-

// Copyright (C) 2001-2021 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 */
Revision:	1166
Committed:	Tue Oct 26 14:22:36 2021 UTC (4 years ago) by rossy
Content type:	text/x-chdr
File size:	12684 byte(s)
Log Message:	Daodan: Replace MinGW build env with an up-to-date MSYS2 env
#	Content
1	// Stack implementation -- C++ --
2
3	// Copyright (C) 2001-2021 Free Software Foundation, Inc.
4	//
5	// This file is part of the GNU ISO C++ Library. This library is free
6	// software; you can redistribute it and/or modify it under the
7	// terms of the GNU General Public License as published by the
8	// Free Software Foundation; either version 3, or (at your option)
9	// any later version.
10
11	// This library is distributed in the hope that it will be useful,
12	// but WITHOUT ANY WARRANTY; without even the implied warranty of
13	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	// GNU General Public License for more details.
15
16	// Under Section 7 of GPL version 3, you are granted additional
17	// permissions described in the GCC Runtime Library Exception, version
18	// 3.1, as published by the Free Software Foundation.
19
20	// You should have received a copy of the GNU General Public License and
21	// a copy of the GCC Runtime Library Exception along with this program;
22	// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23	// <http://www.gnu.org/licenses/>.
24
25	/*
26	*
27	* Copyright (c) 1994
28	* Hewlett-Packard Company
29	*
30	* Permission to use, copy, modify, distribute and sell this software
31	* and its documentation for any purpose is hereby granted without fee,
32	* provided that the above copyright notice appear in all copies and
33	* that both that copyright notice and this permission notice appear
34	* in supporting documentation. Hewlett-Packard Company makes no
35	* representations about the suitability of this software for any
36	* purpose. It is provided "as is" without express or implied warranty.
37	*
38	*
39	* Copyright (c) 1996,1997
40	* Silicon Graphics Computer Systems, Inc.
41	*
42	* Permission to use, copy, modify, distribute and sell this software
43	* and its documentation for any purpose is hereby granted without fee,
44	* provided that the above copyright notice appear in all copies and
45	* that both that copyright notice and this permission notice appear
46	* in supporting documentation. Silicon Graphics makes no
47	* representations about the suitability of this software for any
48	* purpose. It is provided "as is" without express or implied warranty.
49	*/
50
51	/** @file bits/stl_stack.h
52	* This is an internal header file, included by other library headers.
53	* Do not attempt to use it directly. @headername{stack}
54	*/
55
56	#ifndef _STL_STACK_H
57	#define _STL_STACK_H 1
58
59	#include <bits/concept_check.h>
60	#include <debug/debug.h>
61	#if __cplusplus >= 201103L
62	# include <bits/uses_allocator.h>
63	#endif
64
65	namespace std _GLIBCXX_VISIBILITY(default)
66	{
67	_GLIBCXX_BEGIN_NAMESPACE_VERSION
68
69	/**
70	* @brief A standard container giving FILO behavior.
71	*
72	* @ingroup sequences
73	*
74	* @tparam _Tp Type of element.
75	* @tparam _Sequence Type of underlying sequence, defaults to deque<_Tp>.
76	*
77	* Meets many of the requirements of a
78	* <a href="tables.html#65">container</a>,
79	* but does not define anything to do with iterators. Very few of the
80	* other standard container interfaces are defined.
81	*
82	* This is not a true container, but an @e adaptor. It holds
83	* another container, and provides a wrapper interface to that
84	* container. The wrapper is what enforces strict
85	* first-in-last-out %stack behavior.
86	*
87	* The second template parameter defines the type of the underlying
88	* sequence/container. It defaults to std::deque, but it can be
89	* any type that supports @c back, @c push_back, and @c pop_back,
90	* such as std::list, std::vector, or an appropriate user-defined
91	* type.
92	*
93	* Members not found in @a normal containers are @c container_type,
94	* which is a typedef for the second Sequence parameter, and @c
95	* push, @c pop, and @c top, which are standard %stack/FILO
96	* operations.
97	*/
98	template<typename _Tp, typename _Sequence = deque<_Tp> >
99	class stack
100	{
101	#ifdef _GLIBCXX_CONCEPT_CHECKS
102	// concept requirements
103	typedef typename _Sequence::value_type _Sequence_value_type;
104	# if __cplusplus < 201103L
105	__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
106	__glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
107	# endif
108	__glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
109	#endif
110
111	template<typename _Tp1, typename _Seq1>
112	friend bool
113	operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
114
115	template<typename _Tp1, typename _Seq1>
116	friend bool
117	operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
118
119	#if __cpp_lib_three_way_comparison
120	template<typename _Tp1, three_way_comparable _Seq1>
121	friend compare_three_way_result_t<_Seq1>
122	operator<=>(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
123	#endif
124
125	#if __cplusplus >= 201103L
126	template<typename _Alloc>
127	using _Uses = typename
128	enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
129
130	#if __cplusplus >= 201703L
131	// _GLIBCXX_RESOLVE_LIB_DEFECTS
132	// 2566. Requirements on the first template parameter of container
133	// adaptors
134	static_assert(is_same<_Tp, typename _Sequence::value_type>::value,
135	"value_type must be the same as the underlying container");
136	#endif // C++17
137	#endif // C++11
138
139	public:
140	typedef typename _Sequence::value_type value_type;
141	typedef typename _Sequence::reference reference;
142	typedef typename _Sequence::const_reference const_reference;
143	typedef typename _Sequence::size_type size_type;
144	typedef _Sequence container_type;
145
146	protected:
147	// See queue::c for notes on this name.
148	_Sequence c;
149
150	public:
151	// XXX removed old def ctor, added def arg to this one to match 14882
152	/**
153	* @brief Default constructor creates no elements.
154	*/
155	#if __cplusplus < 201103L
156	explicit
157	stack(const _Sequence& __c = _Sequence())
158	: c(__c) { }
159	#else
160	template<typename _Seq = _Sequence, typename _Requires = typename
161	enable_if<is_default_constructible<_Seq>::value>::type>
162	stack()
163	: c() { }
164
165	explicit
166	stack(const _Sequence& __c)
167	: c(__c) { }
168
169	explicit
170	stack(_Sequence&& __c)
171	: c(std::move(__c)) { }
172
173	template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
174	explicit
175	stack(const _Alloc& __a)
176	: c(__a) { }
177
178	template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
179	stack(const _Sequence& __c, const _Alloc& __a)
180	: c(__c, __a) { }
181
182	template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
183	stack(_Sequence&& __c, const _Alloc& __a)
184	: c(std::move(__c), __a) { }
185
186	template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
187	stack(const stack& __q, const _Alloc& __a)
188	: c(__q.c, __a) { }
189
190	template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
191	stack(stack&& __q, const _Alloc& __a)
192	: c(std::move(__q.c), __a) { }
193	#endif
194
195	/**
196	* Returns true if the %stack is empty.
197	*/
198	_GLIBCXX_NODISCARD bool
199	empty() const
200	{ return c.empty(); }
201
202	/** Returns the number of elements in the %stack. */
203	size_type
204	size() const
205	{ return c.size(); }
206
207	/**
208	* Returns a read/write reference to the data at the first
209	* element of the %stack.
210	*/
211	reference
212	top()
213	{
214	__glibcxx_requires_nonempty();
215	return c.back();
216	}
217
218	/**
219	* Returns a read-only (constant) reference to the data at the first
220	* element of the %stack.
221	*/
222	const_reference
223	top() const
224	{
225	__glibcxx_requires_nonempty();
226	return c.back();
227	}
228
229	/**
230	* @brief Add data to the top of the %stack.
231	* @param __x Data to be added.
232	*
233	* This is a typical %stack operation. The function creates an
234	* element at the top of the %stack and assigns the given data
235	* to it. The time complexity of the operation depends on the
236	* underlying sequence.
237	*/
238	void
239	push(const value_type& __x)
240	{ c.push_back(__x); }
241
242	#if __cplusplus >= 201103L
243	void
244	push(value_type&& __x)
245	{ c.push_back(std::move(__x)); }
246
247	#if __cplusplus > 201402L
248	template<typename... _Args>
249	decltype(auto)
250	emplace(_Args&&... __args)
251	{ return c.emplace_back(std::forward<_Args>(__args)...); }
252	#else
253	template<typename... _Args>
254	void
255	emplace(_Args&&... __args)
256	{ c.emplace_back(std::forward<_Args>(__args)...); }
257	#endif
258	#endif
259
260	/**
261	* @brief Removes first element.
262	*
263	* This is a typical %stack operation. It shrinks the %stack
264	* by one. The time complexity of the operation depends on the
265	* underlying sequence.
266	*
267	* Note that no data is returned, and if the first element's
268	* data is needed, it should be retrieved before pop() is
269	* called.
270	*/
271	void
272	pop()
273	{
274	__glibcxx_requires_nonempty();
275	c.pop_back();
276	}
277
278	#if __cplusplus >= 201103L
279	void
280	swap(stack& __s)
281	#if __cplusplus > 201402L \|\| !defined(__STRICT_ANSI__) // c++1z or gnu++11
282	noexcept(__is_nothrow_swappable<_Sequence>::value)
283	#else
284	noexcept(__is_nothrow_swappable<_Tp>::value)
285	#endif
286	{
287	using std::swap;
288	swap(c, __s.c);
289	}
290	#endif // __cplusplus >= 201103L
291	};
292
293	#if __cpp_deduction_guides >= 201606
294	template<typename _Container,
295	typename = _RequireNotAllocator<_Container>>
296	stack(_Container) -> stack<typename _Container::value_type, _Container>;
297
298	template<typename _Container, typename _Allocator,
299	typename = _RequireNotAllocator<_Container>,
300	typename = _RequireAllocator<_Allocator>>
301	stack(_Container, _Allocator)
302	-> stack<typename _Container::value_type, _Container>;
303	#endif
304
305	/**
306	* @brief Stack equality comparison.
307	* @param __x A %stack.
308	* @param __y A %stack of the same type as @a __x.
309	* @return True iff the size and elements of the stacks are equal.
310	*
311	* This is an equivalence relation. Complexity and semantics
312	* depend on the underlying sequence type, but the expected rules
313	* are: this relation is linear in the size of the sequences, and
314	* stacks are considered equivalent if their sequences compare
315	* equal.
316	*/
317	template<typename _Tp, typename _Seq>
318	inline bool
319	operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
320	{ return __x.c == __y.c; }
321
322	/**
323	* @brief Stack ordering relation.
324	* @param __x A %stack.
325	* @param __y A %stack of the same type as @a x.
326	* @return True iff @a x is lexicographically less than @a __y.
327	*
328	* This is an total ordering relation. Complexity and semantics
329	* depend on the underlying sequence type, but the expected rules
330	* are: this relation is linear in the size of the sequences, the
331	* elements must be comparable with @c <, and
332	* std::lexicographical_compare() is usually used to make the
333	* determination.
334	*/
335	template<typename _Tp, typename _Seq>
336	inline bool
337	operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
338	{ return __x.c < __y.c; }
339
340	/// Based on operator==
341	template<typename _Tp, typename _Seq>
342	inline bool
343	operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
344	{ return !(__x == __y); }
345
346	/// Based on operator<
347	template<typename _Tp, typename _Seq>
348	inline bool
349	operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
350	{ return __y < __x; }
351
352	/// Based on operator<
353	template<typename _Tp, typename _Seq>
354	inline bool
355	operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
356	{ return !(__y < __x); }
357
358	/// Based on operator<
359	template<typename _Tp, typename _Seq>
360	inline bool
361	operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
362	{ return !(__x < __y); }
363
364	#if __cpp_lib_three_way_comparison
365	template<typename _Tp, three_way_comparable _Seq>
366	inline compare_three_way_result_t<_Seq>
367	operator<=>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
368	{ return __x.c <=> __y.c; }
369	#endif
370
371	#if __cplusplus >= 201103L
372	template<typename _Tp, typename _Seq>
373	inline
374	#if __cplusplus > 201402L \|\| !defined(__STRICT_ANSI__) // c++1z or gnu++11
375	// Constrained free swap overload, see p0185r1
376	typename enable_if<__is_swappable<_Seq>::value>::type
377	#else
378	void
379	#endif
380	swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
381	noexcept(noexcept(__x.swap(__y)))
382	{ __x.swap(__y); }
383
384	template<typename _Tp, typename _Seq, typename _Alloc>
385	struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
386	: public uses_allocator<_Seq, _Alloc>::type { };
387	#endif // __cplusplus >= 201103L
388
389	_GLIBCXX_END_NAMESPACE_VERSION
390	} // namespace
391
392	#endif /* _STL_STACK_H */