1 | // Stack implementation -*- C++ -*- |
2 | |
3 | // Copyright (C) 2001-2019 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 __cplusplus >= 201103L |
120 | template<typename _Alloc> |
121 | using _Uses = typename |
122 | enable_if<uses_allocator<_Sequence, _Alloc>::value>::type; |
123 | |
124 | #if __cplusplus >= 201703L |
125 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
126 | // 2566. Requirements on the first template parameter of container |
127 | // adaptors |
128 | static_assert(is_same<_Tp, typename _Sequence::value_type>::value, |
129 | "value_type must be the same as the underlying container" ); |
130 | #endif // C++17 |
131 | #endif // C++11 |
132 | |
133 | public: |
134 | typedef typename _Sequence::value_type value_type; |
135 | typedef typename _Sequence::reference reference; |
136 | typedef typename _Sequence::const_reference const_reference; |
137 | typedef typename _Sequence::size_type size_type; |
138 | typedef _Sequence container_type; |
139 | |
140 | protected: |
141 | // See queue::c for notes on this name. |
142 | _Sequence c; |
143 | |
144 | public: |
145 | // XXX removed old def ctor, added def arg to this one to match 14882 |
146 | /** |
147 | * @brief Default constructor creates no elements. |
148 | */ |
149 | #if __cplusplus < 201103L |
150 | explicit |
151 | stack(const _Sequence& __c = _Sequence()) |
152 | : c(__c) { } |
153 | #else |
154 | template<typename _Seq = _Sequence, typename _Requires = typename |
155 | enable_if<is_default_constructible<_Seq>::value>::type> |
156 | stack() |
157 | : c() { } |
158 | |
159 | explicit |
160 | stack(const _Sequence& __c) |
161 | : c(__c) { } |
162 | |
163 | explicit |
164 | stack(_Sequence&& __c) |
165 | : c(std::move(__c)) { } |
166 | |
167 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
168 | explicit |
169 | stack(const _Alloc& __a) |
170 | : c(__a) { } |
171 | |
172 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
173 | stack(const _Sequence& __c, const _Alloc& __a) |
174 | : c(__c, __a) { } |
175 | |
176 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
177 | stack(_Sequence&& __c, const _Alloc& __a) |
178 | : c(std::move(__c), __a) { } |
179 | |
180 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
181 | stack(const stack& __q, const _Alloc& __a) |
182 | : c(__q.c, __a) { } |
183 | |
184 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
185 | stack(stack&& __q, const _Alloc& __a) |
186 | : c(std::move(__q.c), __a) { } |
187 | #endif |
188 | |
189 | /** |
190 | * Returns true if the %stack is empty. |
191 | */ |
192 | _GLIBCXX_NODISCARD bool |
193 | empty() const |
194 | { return c.empty(); } |
195 | |
196 | /** Returns the number of elements in the %stack. */ |
197 | size_type |
198 | size() const |
199 | { return c.size(); } |
200 | |
201 | /** |
202 | * Returns a read/write reference to the data at the first |
203 | * element of the %stack. |
204 | */ |
205 | reference |
206 | top() |
207 | { |
208 | __glibcxx_requires_nonempty(); |
209 | return c.back(); |
210 | } |
211 | |
212 | /** |
213 | * Returns a read-only (constant) reference to the data at the first |
214 | * element of the %stack. |
215 | */ |
216 | const_reference |
217 | top() const |
218 | { |
219 | __glibcxx_requires_nonempty(); |
220 | return c.back(); |
221 | } |
222 | |
223 | /** |
224 | * @brief Add data to the top of the %stack. |
225 | * @param __x Data to be added. |
226 | * |
227 | * This is a typical %stack operation. The function creates an |
228 | * element at the top of the %stack and assigns the given data |
229 | * to it. The time complexity of the operation depends on the |
230 | * underlying sequence. |
231 | */ |
232 | void |
233 | push(const value_type& __x) |
234 | { c.push_back(__x); } |
235 | |
236 | #if __cplusplus >= 201103L |
237 | void |
238 | push(value_type&& __x) |
239 | { c.push_back(std::move(__x)); } |
240 | |
241 | #if __cplusplus > 201402L |
242 | template<typename... _Args> |
243 | decltype(auto) |
244 | emplace(_Args&&... __args) |
245 | { return c.emplace_back(std::forward<_Args>(__args)...); } |
246 | #else |
247 | template<typename... _Args> |
248 | void |
249 | emplace(_Args&&... __args) |
250 | { c.emplace_back(std::forward<_Args>(__args)...); } |
251 | #endif |
252 | #endif |
253 | |
254 | /** |
255 | * @brief Removes first element. |
256 | * |
257 | * This is a typical %stack operation. It shrinks the %stack |
258 | * by one. The time complexity of the operation depends on the |
259 | * underlying sequence. |
260 | * |
261 | * Note that no data is returned, and if the first element's |
262 | * data is needed, it should be retrieved before pop() is |
263 | * called. |
264 | */ |
265 | void |
266 | pop() |
267 | { |
268 | __glibcxx_requires_nonempty(); |
269 | c.pop_back(); |
270 | } |
271 | |
272 | #if __cplusplus >= 201103L |
273 | void |
274 | swap(stack& __s) |
275 | #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 |
276 | noexcept(__is_nothrow_swappable<_Sequence>::value) |
277 | #else |
278 | noexcept(__is_nothrow_swappable<_Tp>::value) |
279 | #endif |
280 | { |
281 | using std::swap; |
282 | swap(c, __s.c); |
283 | } |
284 | #endif // __cplusplus >= 201103L |
285 | }; |
286 | |
287 | #if __cpp_deduction_guides >= 201606 |
288 | template<typename _Container, |
289 | typename = _RequireNotAllocator<_Container>> |
290 | stack(_Container) -> stack<typename _Container::value_type, _Container>; |
291 | |
292 | template<typename _Container, typename _Allocator, |
293 | typename = _RequireNotAllocator<_Container>, |
294 | typename = _RequireAllocator<_Allocator>> |
295 | stack(_Container, _Allocator) |
296 | -> stack<typename _Container::value_type, _Container>; |
297 | #endif |
298 | |
299 | /** |
300 | * @brief Stack equality comparison. |
301 | * @param __x A %stack. |
302 | * @param __y A %stack of the same type as @a __x. |
303 | * @return True iff the size and elements of the stacks are equal. |
304 | * |
305 | * This is an equivalence relation. Complexity and semantics |
306 | * depend on the underlying sequence type, but the expected rules |
307 | * are: this relation is linear in the size of the sequences, and |
308 | * stacks are considered equivalent if their sequences compare |
309 | * equal. |
310 | */ |
311 | template<typename _Tp, typename _Seq> |
312 | inline bool |
313 | operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) |
314 | { return __x.c == __y.c; } |
315 | |
316 | /** |
317 | * @brief Stack ordering relation. |
318 | * @param __x A %stack. |
319 | * @param __y A %stack of the same type as @a x. |
320 | * @return True iff @a x is lexicographically less than @a __y. |
321 | * |
322 | * This is an total ordering relation. Complexity and semantics |
323 | * depend on the underlying sequence type, but the expected rules |
324 | * are: this relation is linear in the size of the sequences, the |
325 | * elements must be comparable with @c <, and |
326 | * std::lexicographical_compare() is usually used to make the |
327 | * determination. |
328 | */ |
329 | template<typename _Tp, typename _Seq> |
330 | inline bool |
331 | operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) |
332 | { return __x.c < __y.c; } |
333 | |
334 | /// Based on operator== |
335 | template<typename _Tp, typename _Seq> |
336 | inline bool |
337 | operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) |
338 | { return !(__x == __y); } |
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 __y < __x; } |
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 !(__x < __y); } |
357 | |
358 | #if __cplusplus >= 201103L |
359 | template<typename _Tp, typename _Seq> |
360 | inline |
361 | #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 |
362 | // Constrained free swap overload, see p0185r1 |
363 | typename enable_if<__is_swappable<_Seq>::value>::type |
364 | #else |
365 | void |
366 | #endif |
367 | swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y) |
368 | noexcept(noexcept(__x.swap(__y))) |
369 | { __x.swap(__y); } |
370 | |
371 | template<typename _Tp, typename _Seq, typename _Alloc> |
372 | struct uses_allocator<stack<_Tp, _Seq>, _Alloc> |
373 | : public uses_allocator<_Seq, _Alloc>::type { }; |
374 | #endif // __cplusplus >= 201103L |
375 | |
376 | _GLIBCXX_END_NAMESPACE_VERSION |
377 | } // namespace |
378 | |
379 | #endif /* _STL_STACK_H */ |
380 | |