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 */ |
393 | |