1 // Stack implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2016 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_front, 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 // concept requirements 102 typedef typename _Sequence::value_type _Sequence_value_type; 103 #if __cplusplus < 201103L 104 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 105 __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept) 106 #endif 107 __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept) 108 109 template<typename _Tp1, typename _Seq1> 110 friend bool 111 operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&); 112 113 template<typename _Tp1, typename _Seq1> 114 friend bool 115 operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&); 116 117 #if __cplusplus >= 201103L 118 template<typename _Alloc> 119 using _Uses = typename 120 enable_if<uses_allocator<_Sequence, _Alloc>::value>::type; 121 #endif 122 123 public: 124 typedef typename _Sequence::value_type value_type; 125 typedef typename _Sequence::reference reference; 126 typedef typename _Sequence::const_reference const_reference; 127 typedef typename _Sequence::size_type size_type; 128 typedef _Sequence container_type; 129 130 protected: 131 // See queue::c for notes on this name. 132 _Sequence c; 133 134 public: 135 // XXX removed old def ctor, added def arg to this one to match 14882 136 /** 137 * @brief Default constructor creates no elements. 138 */ 139 #if __cplusplus < 201103L 140 explicit 141 stack(const _Sequence& __c = _Sequence()) 142 : c(__c) { } 143 #else 144 explicit 145 stack(const _Sequence& __c) 146 : c(__c) { } 147 148 explicit 149 stack(_Sequence&& __c = _Sequence()) 150 : c(std::move(__c)) { } 151 152 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 153 explicit 154 stack(const _Alloc& __a) 155 : c(__a) { } 156 157 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 158 stack(const _Sequence& __c, const _Alloc& __a) 159 : c(__c, __a) { } 160 161 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 162 stack(_Sequence&& __c, const _Alloc& __a) 163 : c(std::move(__c), __a) { } 164 165 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 166 stack(const stack& __q, const _Alloc& __a) 167 : c(__q.c, __a) { } 168 169 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 170 stack(stack&& __q, const _Alloc& __a) 171 : c(std::move(__q.c), __a) { } 172 #endif 173 174 /** 175 * Returns true if the %stack is empty. 176 */ 177 bool 178 empty() const 179 { return c.empty(); } 180 181 /** Returns the number of elements in the %stack. */ 182 size_type 183 size() const 184 { return c.size(); } 185 186 /** 187 * Returns a read/write reference to the data at the first 188 * element of the %stack. 189 */ 190 reference 191 top() 192 { 193 __glibcxx_requires_nonempty(); 194 return c.back(); 195 } 196 197 /** 198 * Returns a read-only (constant) reference to the data at the first 199 * element of the %stack. 200 */ 201 const_reference 202 top() const 203 { 204 __glibcxx_requires_nonempty(); 205 return c.back(); 206 } 207 208 /** 209 * @brief Add data to the top of the %stack. 210 * @param __x Data to be added. 211 * 212 * This is a typical %stack operation. The function creates an 213 * element at the top of the %stack and assigns the given data 214 * to it. The time complexity of the operation depends on the 215 * underlying sequence. 216 */ 217 void 218 push(const value_type& __x) 219 { c.push_back(__x); } 220 221 #if __cplusplus >= 201103L 222 void 223 push(value_type&& __x) 224 { c.push_back(std::move(__x)); } 225 226 template<typename... _Args> 227 void 228 emplace(_Args&&... __args) 229 { c.emplace_back(std::forward<_Args>(__args)...); } 230 #endif 231 232 /** 233 * @brief Removes first element. 234 * 235 * This is a typical %stack operation. It shrinks the %stack 236 * by one. The time complexity of the operation depends on the 237 * underlying sequence. 238 * 239 * Note that no data is returned, and if the first element's 240 * data is needed, it should be retrieved before pop() is 241 * called. 242 */ 243 void 244 pop() 245 { 246 __glibcxx_requires_nonempty(); 247 c.pop_back(); 248 } 249 250 #if __cplusplus >= 201103L 251 void 252 swap(stack& __s) 253 noexcept(__is_nothrow_swappable<_Tp>::value) 254 { 255 using std::swap; 256 swap(c, __s.c); 257 } 258 #endif 259 }; 260 261 /** 262 * @brief Stack equality comparison. 263 * @param __x A %stack. 264 * @param __y A %stack of the same type as @a __x. 265 * @return True iff the size and elements of the stacks are equal. 266 * 267 * This is an equivalence relation. Complexity and semantics 268 * depend on the underlying sequence type, but the expected rules 269 * are: this relation is linear in the size of the sequences, and 270 * stacks are considered equivalent if their sequences compare 271 * equal. 272 */ 273 template<typename _Tp, typename _Seq> 274 inline bool 275 operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 276 { return __x.c == __y.c; } 277 278 /** 279 * @brief Stack ordering relation. 280 * @param __x A %stack. 281 * @param __y A %stack of the same type as @a x. 282 * @return True iff @a x is lexicographically less than @a __y. 283 * 284 * This is an total ordering relation. Complexity and semantics 285 * depend on the underlying sequence type, but the expected rules 286 * are: this relation is linear in the size of the sequences, the 287 * elements must be comparable with @c <, and 288 * std::lexicographical_compare() is usually used to make the 289 * determination. 290 */ 291 template<typename _Tp, typename _Seq> 292 inline bool 293 operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 294 { return __x.c < __y.c; } 295 296 /// Based on operator== 297 template<typename _Tp, typename _Seq> 298 inline bool 299 operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 300 { return !(__x == __y); } 301 302 /// Based on operator< 303 template<typename _Tp, typename _Seq> 304 inline bool 305 operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 306 { return __y < __x; } 307 308 /// Based on operator< 309 template<typename _Tp, typename _Seq> 310 inline bool 311 operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 312 { return !(__y < __x); } 313 314 /// Based on operator< 315 template<typename _Tp, typename _Seq> 316 inline bool 317 operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) 318 { return !(__x < __y); } 319 320 #if __cplusplus >= 201103L 321 template<typename _Tp, typename _Seq> 322 inline void 323 swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y) 324 noexcept(noexcept(__x.swap(__y))) 325 { __x.swap(__y); } 326 327 template<typename _Tp, typename _Seq, typename _Alloc> 328 struct uses_allocator<stack<_Tp, _Seq>, _Alloc> 329 : public uses_allocator<_Seq, _Alloc>::type { }; 330 #endif 331 332 _GLIBCXX_END_NAMESPACE_VERSION 333 } // namespace 334 335 #endif /* _STL_STACK_H */ 336