1 // Stack implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2018 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 #endif 124 125 public: 126 typedef typename _Sequence::value_type value_type; 127 typedef typename _Sequence::reference reference; 128 typedef typename _Sequence::const_reference const_reference; 129 typedef typename _Sequence::size_type size_type; 130 typedef _Sequence container_type; 131 132 protected: 133 // See queue::c for notes on this name. 134 _Sequence c; 135 136 public: 137 // XXX removed old def ctor, added def arg to this one to match 14882 138 /** 139 * @brief Default constructor creates no elements. 140 */ 141 #if __cplusplus < 201103L 142 explicit 143 stack(const _Sequence& __c = _Sequence()) 144 : c(__c) { } 145 #else 146 template<typename _Seq = _Sequence, typename _Requires = typename 147 enable_if<is_default_constructible<_Seq>::value>::type> 148 stack() 149 : c() { } 150 151 explicit 152 stack(const _Sequence& __c) 153 : c(__c) { } 154 155 explicit 156 stack(_Sequence&& __c) 157 : c(std::move(__c)) { } 158 159 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 160 explicit 161 stack(const _Alloc& __a) 162 : c(__a) { } 163 164 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 165 stack(const _Sequence& __c, const _Alloc& __a) 166 : c(__c, __a) { } 167 168 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 169 stack(_Sequence&& __c, const _Alloc& __a) 170 : c(std::move(__c), __a) { } 171 172 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 173 stack(const stack& __q, const _Alloc& __a) 174 : c(__q.c, __a) { } 175 176 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 177 stack(stack&& __q, const _Alloc& __a) 178 : c(std::move(__q.c), __a) { } 179 #endif 180 181 /** 182 * Returns true if the %stack is empty. 183 */ 184 bool 185 empty() const 186 { return c.empty(); } 187 188 /** Returns the number of elements in the %stack. */ 189 size_type 190 size() const 191 { return c.size(); } 192 193 /** 194 * Returns a read/write reference to the data at the first 195 * element of the %stack. 196 */ 197 reference 198 top() 199 { 200 __glibcxx_requires_nonempty(); 201 return c.back(); 202 } 203 204 /** 205 * Returns a read-only (constant) reference to the data at the first 206 * element of the %stack. 207 */ 208 const_reference 209 top() const 210 { 211 __glibcxx_requires_nonempty(); 212 return c.back(); 213 } 214 215 /** 216 * @brief Add data to the top of the %stack. 217 * @param __x Data to be added. 218 * 219 * This is a typical %stack operation. The function creates an 220 * element at the top of the %stack and assigns the given data 221 * to it. The time complexity of the operation depends on the 222 * underlying sequence. 223 */ 224 void 225 push(const value_type& __x) 226 { c.push_back(__x); } 227 228 #if __cplusplus >= 201103L 229 void 230 push(value_type&& __x) 231 { c.push_back(std::move(__x)); } 232 233 #if __cplusplus > 201402L 234 template<typename... _Args> 235 decltype(auto) 236 emplace(_Args&&... __args) 237 { return c.emplace_back(std::forward<_Args>(__args)...); } 238 #else 239 template<typename... _Args> 240 void 241 emplace(_Args&&... __args) 242 { c.emplace_back(std::forward<_Args>(__args)...); } 243 #endif 244 #endif 245 246 /** 247 * @brief Removes first element. 248 * 249 * This is a typical %stack operation. It shrinks the %stack 250 * by one. The time complexity of the operation depends on the 251 * underlying sequence. 252 * 253 * Note that no data is returned, and if the first element's 254 * data is needed, it should be retrieved before pop() is 255 * called. 256 */ 257 void 258 pop() 259 { 260 __glibcxx_requires_nonempty(); 261 c.pop_back(); 262 } 263 264 #if __cplusplus >= 201103L 265 void 266 swap(stack& __s) 267 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 268 noexcept(__is_nothrow_swappable<_Sequence>::value) 269 #else 270 noexcept(__is_nothrow_swappable<_Tp>::value) 271 #endif 272 { 273 using std::swap; 274 swap(c, __s.c); 275 } 276 #endif // __cplusplus >= 201103L 277 }; 278 279 #if __cpp_deduction_guides >= 201606 280 template<typename _Container, 281 typename = enable_if_t<!__is_allocator<_Container>::value>> 282 stack(_Container) -> stack<typename _Container::value_type, _Container>; 283 284 template<typename _Container, typename _Allocator, 285 typename = enable_if_t<!__is_allocator<_Container>::value>, 286 typename = enable_if_t<__is_allocator<_Allocator>::value>> 287 stack(_Container, _Allocator) 288 -> stack<typename _Container::value_type, _Container>; 289 #endif 290 291 /** 292 * @brief Stack equality comparison. 293 * @param __x A %stack. 294 * @param __y A %stack of the same type as @a __x. 295 * @return True iff the size and elements of the stacks are equal. 296 * 297 * This is an equivalence relation. Complexity and semantics 298 * depend on the underlying sequence type, but the expected rules 299 * are: this relation is linear in the size of the sequences, and 300 * stacks are considered equivalent if their sequences compare 301 * equal. 302 */ 303 template<typename _Tp, typename _Seq> 304 inline bool 305 operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 306 { return __x.c == __y.c; } 307 308 /** 309 * @brief Stack ordering relation. 310 * @param __x A %stack. 311 * @param __y A %stack of the same type as @a x. 312 * @return True iff @a x is lexicographically less than @a __y. 313 * 314 * This is an total ordering relation. Complexity and semantics 315 * depend on the underlying sequence type, but the expected rules 316 * are: this relation is linear in the size of the sequences, the 317 * elements must be comparable with @c <, and 318 * std::lexicographical_compare() is usually used to make the 319 * determination. 320 */ 321 template<typename _Tp, typename _Seq> 322 inline bool 323 operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 324 { return __x.c < __y.c; } 325 326 /// Based on operator== 327 template<typename _Tp, typename _Seq> 328 inline bool 329 operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 330 { return !(__x == __y); } 331 332 /// Based on operator< 333 template<typename _Tp, typename _Seq> 334 inline bool 335 operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 336 { return __y < __x; } 337 338 /// Based on operator< 339 template<typename _Tp, typename _Seq> 340 inline bool 341 operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 342 { return !(__y < __x); } 343 344 /// Based on operator< 345 template<typename _Tp, typename _Seq> 346 inline bool 347 operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 348 { return !(__x < __y); } 349 350 #if __cplusplus >= 201103L 351 template<typename _Tp, typename _Seq> 352 inline 353 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 354 // Constrained free swap overload, see p0185r1 355 typename enable_if<__is_swappable<_Seq>::value>::type 356 #else 357 void 358 #endif 359 swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y) 360 noexcept(noexcept(__x.swap(__y))) 361 { __x.swap(__y); } 362 363 template<typename _Tp, typename _Seq, typename _Alloc> 364 struct uses_allocator<stack<_Tp, _Seq>, _Alloc> 365 : public uses_allocator<_Seq, _Alloc>::type { }; 366 #endif // __cplusplus >= 201103L 367 368 _GLIBCXX_END_NAMESPACE_VERSION 369 } // namespace 370 371 #endif /* _STL_STACK_H */ 372