libstdc++

stl_stack.h
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1 // Stack implementation -*- C++ -*-
2
3 // Copyright (C) 2001-2013 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
62 namespace std _GLIBCXX_VISIBILITY(default)
63 {
64 _GLIBCXX_BEGIN_NAMESPACE_VERSION
65
66 /**
67 * @brief A standard container giving FILO behavior.
68 *
69 * @ingroup sequences
70 *
71 * @tparam _Tp Type of element.
72 * @tparam _Sequence Type of underlying sequence, defaults to deque<_Tp>.
73 *
74 * Meets many of the requirements of a
75 * <a href="tables.html#65">container</a>,
76 * but does not define anything to do with iterators. Very few of the
77 * other standard container interfaces are defined.
78 *
79 * This is not a true container, but an @e adaptor. It holds
80 * another container, and provides a wrapper interface to that
81 * container. The wrapper is what enforces strict
82 * first-in-last-out %stack behavior.
83 *
84 * The second template parameter defines the type of the underlying
85 * sequence/container. It defaults to std::deque, but it can be
86 * any type that supports @c back, @c push_back, and @c pop_front,
87 * such as std::list, std::vector, or an appropriate user-defined
88 * type.
89 *
90 * Members not found in @a normal containers are @c container_type,
91 * which is a typedef for the second Sequence parameter, and @c
92 * push, @c pop, and @c top, which are standard %stack/FILO
93 * operations.
94 */
95 template<typename _Tp, typename _Sequence = deque<_Tp> >
96 class stack
97 {
98 // concept requirements
99 typedef typename _Sequence::value_type _Sequence_value_type;
100 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
101 __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
102 __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
103
104 template<typename _Tp1, typename _Seq1>
105 friend bool
106 operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
107
108 template<typename _Tp1, typename _Seq1>
109 friend bool
110 operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
111
112 public:
113 typedef typename _Sequence::value_type value_type;
114 typedef typename _Sequence::reference reference;
115 typedef typename _Sequence::const_reference const_reference;
116 typedef typename _Sequence::size_type size_type;
117 typedef _Sequence container_type;
118
119 protected:
120 // See queue::c for notes on this name.
121 _Sequence c;
122
123 public:
124 // XXX removed old def ctor, added def arg to this one to match 14882
125 /**
126 * @brief Default constructor creates no elements.
127 */
128 #if __cplusplus < 201103L
129 explicit
130 stack(const _Sequence& __c = _Sequence())
131 : c(__c) { }
132 #else
133 explicit
134 stack(const _Sequence& __c)
135 : c(__c) { }
136
137 explicit
138 stack(_Sequence&& __c = _Sequence())
139 : c(std::move(__c)) { }
140 #endif
141
142 /**
143 * Returns true if the %stack is empty.
144 */
145 bool
146 empty() const
147 { return c.empty(); }
148
149 /** Returns the number of elements in the %stack. */
150 size_type
151 size() const
152 { return c.size(); }
153
154 /**
155 * Returns a read/write reference to the data at the first
156 * element of the %stack.
157 */
158 reference
159 top()
160 {
161 __glibcxx_requires_nonempty();
162 return c.back();
163 }
164
165 /**
166 * Returns a read-only (constant) reference to the data at the first
167 * element of the %stack.
168 */
169 const_reference
170 top() const
171 {
172 __glibcxx_requires_nonempty();
173 return c.back();
174 }
175
176 /**
177 * @brief Add data to the top of the %stack.
178 * @param __x Data to be added.
179 *
180 * This is a typical %stack operation. The function creates an
181 * element at the top of the %stack and assigns the given data
182 * to it. The time complexity of the operation depends on the
183 * underlying sequence.
184 */
185 void
186 push(const value_type& __x)
187 { c.push_back(__x); }
188
189 #if __cplusplus >= 201103L
190 void
191 push(value_type&& __x)
192 { c.push_back(std::move(__x)); }
193
194 template<typename... _Args>
195 void
196 emplace(_Args&&... __args)
197 { c.emplace_back(std::forward<_Args>(__args)...); }
198 #endif
199
200 /**
201 * @brief Removes first element.
202 *
203 * This is a typical %stack operation. It shrinks the %stack
204 * by one. The time complexity of the operation depends on the
205 * underlying sequence.
206 *
207 * Note that no data is returned, and if the first element's
208 * data is needed, it should be retrieved before pop() is
209 * called.
210 */
211 void
212 pop()
213 {
214 __glibcxx_requires_nonempty();
215 c.pop_back();
216 }
217
218 #if __cplusplus >= 201103L
219 void
220 swap(stack& __s)
221 noexcept(noexcept(swap(c, __s.c)))
222 {
223 using std::swap;
224 swap(c, __s.c);
225 }
226 #endif
227 };
228
229 /**
230 * @brief Stack equality comparison.
231 * @param __x A %stack.
232 * @param __y A %stack of the same type as @a __x.
233 * @return True iff the size and elements of the stacks are equal.
234 *
235 * This is an equivalence relation. Complexity and semantics
236 * depend on the underlying sequence type, but the expected rules
237 * are: this relation is linear in the size of the sequences, and
238 * stacks are considered equivalent if their sequences compare
239 * equal.
240 */
241 template<typename _Tp, typename _Seq>
242 inline bool
243 operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
244 { return __x.c == __y.c; }
245
246 /**
247 * @brief Stack ordering relation.
248 * @param __x A %stack.
249 * @param __y A %stack of the same type as @a x.
250 * @return True iff @a x is lexicographically less than @a __y.
251 *
252 * This is an total ordering relation. Complexity and semantics
253 * depend on the underlying sequence type, but the expected rules
254 * are: this relation is linear in the size of the sequences, the
255 * elements must be comparable with @c <, and
256 * std::lexicographical_compare() is usually used to make the
257 * determination.
258 */
259 template<typename _Tp, typename _Seq>
260 inline bool
261 operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
262 { return __x.c < __y.c; }
263
264 /// Based on operator==
265 template<typename _Tp, typename _Seq>
266 inline bool
267 operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
268 { return !(__x == __y); }
269
270 /// Based on operator<
271 template<typename _Tp, typename _Seq>
272 inline bool
273 operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
274 { return __y < __x; }
275
276 /// Based on operator<
277 template<typename _Tp, typename _Seq>
278 inline bool
279 operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
280 { return !(__y < __x); }
281
282 /// Based on operator<
283 template<typename _Tp, typename _Seq>
284 inline bool
285 operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
286 { return !(__x < __y); }
287
288 #if __cplusplus >= 201103L
289 template<typename _Tp, typename _Seq>
290 inline void
291 swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
292 noexcept(noexcept(__x.swap(__y)))
293 { __x.swap(__y); }
294
295 template<typename _Tp, typename _Seq, typename _Alloc>
296 struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
297 : public uses_allocator<_Seq, _Alloc>::type { };
298 #endif
299
300 _GLIBCXX_END_NAMESPACE_VERSION
301 } // namespace
302
303 #endif /* _STL_STACK_H */