libstdc++-v3/include/bits/stl_stack.h

   1 // Stack implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001-2015 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       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
 104       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
 105       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
 106
 107       template<typename _Tp1, typename _Seq1>
 108         friend bool
 109         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 110
 111       template<typename _Tp1, typename _Seq1>
 112         friend bool
 113         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 114
 115     public:
 116       typedef typename _Sequence::value_type                value_type;
 117       typedef typename _Sequence::reference                 reference;
 118       typedef typename _Sequence::const_reference           const_reference;
 119       typedef typename _Sequence::size_type                 size_type;
 120       typedef          _Sequence                            container_type;
 121
 122     protected:
 123       //  See queue::c for notes on this name.
 124       _Sequence c;
 125
 126     public:
 127       // XXX removed old def ctor, added def arg to this one to match 14882
 128       /**
 129        *  @brief  Default constructor creates no elements.
 130        */
 131 #if __cplusplus < 201103L
 132       explicit
 133       stack(const _Sequence& __c = _Sequence())
 134       : c(__c) { }
 135 #else
 136       explicit
 137       stack(const _Sequence& __c)
 138       : c(__c) { }
 139
 140       explicit
 141       stack(_Sequence&& __c = _Sequence())
 142       : c(std::move(__c)) { }
 143 #endif
 144
 145       /**
 146        *  Returns true if the %stack is empty.
 147        */
 148       bool
 149       empty() const
 150       { return c.empty(); }
 151
 152       /**  Returns the number of elements in the %stack.  */
 153       size_type
 154       size() const
 155       { return c.size(); }
 156
 157       /**
 158        *  Returns a read/write reference to the data at the first
 159        *  element of the %stack.
 160        */
 161       reference
 162       top()
 163       {
 164         __glibcxx_requires_nonempty();
 165         return c.back();
 166       }
 167
 168       /**
 169        *  Returns a read-only (constant) reference to the data at the first
 170        *  element of the %stack.
 171        */
 172       const_reference
 173       top() const
 174       {
 175         __glibcxx_requires_nonempty();
 176         return c.back();
 177       }
 178
 179       /**
 180        *  @brief  Add data to the top of the %stack.
 181        *  @param  __x  Data to be added.
 182        *
 183        *  This is a typical %stack operation.  The function creates an
 184        *  element at the top of the %stack and assigns the given data
 185        *  to it.  The time complexity of the operation depends on the
 186        *  underlying sequence.
 187        */
 188       void
 189       push(const value_type& __x)
 190       { c.push_back(__x); }
 191
 192 #if __cplusplus >= 201103L
 193       void
 194       push(value_type&& __x)
 195       { c.push_back(std::move(__x)); }
 196
 197       template<typename... _Args>
 198         void
 199         emplace(_Args&&... __args)
 200         { c.emplace_back(std::forward<_Args>(__args)...); }
 201 #endif
 202
 203       /**
 204        *  @brief  Removes first element.
 205        *
 206        *  This is a typical %stack operation.  It shrinks the %stack
 207        *  by one.  The time complexity of the operation depends on the
 208        *  underlying sequence.
 209        *
 210        *  Note that no data is returned, and if the first element's
 211        *  data is needed, it should be retrieved before pop() is
 212        *  called.
 213        */
 214       void
 215       pop()
 216       {
 217         __glibcxx_requires_nonempty();
 218         c.pop_back();
 219       }
 220
 221 #if __cplusplus >= 201103L
 222       void
 223       swap(stack& __s)
 224       noexcept(noexcept(swap(c, __s.c)))
 225       {
 226         using std::swap;
 227         swap(c, __s.c);
 228       }
 229 #endif
 230     };
 231
 232   /**
 233    *  @brief  Stack equality comparison.
 234    *  @param  __x  A %stack.
 235    *  @param  __y  A %stack of the same type as @a __x.
 236    *  @return  True iff the size and elements of the stacks are equal.
 237    *
 238    *  This is an equivalence relation.  Complexity and semantics
 239    *  depend on the underlying sequence type, but the expected rules
 240    *  are: this relation is linear in the size of the sequences, and
 241    *  stacks are considered equivalent if their sequences compare
 242    *  equal.
 243   */
 244   template<typename _Tp, typename _Seq>
 245     inline bool
 246     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 247     { return __x.c == __y.c; }
 248
 249   /**
 250    *  @brief  Stack ordering relation.
 251    *  @param  __x  A %stack.
 252    *  @param  __y  A %stack of the same type as @a x.
 253    *  @return  True iff @a x is lexicographically less than @a __y.
 254    *
 255    *  This is an total ordering relation.  Complexity and semantics
 256    *  depend on the underlying sequence type, but the expected rules
 257    *  are: this relation is linear in the size of the sequences, the
 258    *  elements must be comparable with @c <, and
 259    *  std::lexicographical_compare() is usually used to make the
 260    *  determination.
 261   */
 262   template<typename _Tp, typename _Seq>
 263     inline bool
 264     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 265     { return __x.c < __y.c; }
 266
 267   /// Based on operator==
 268   template<typename _Tp, typename _Seq>
 269     inline bool
 270     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 271     { return !(__x == __y); }
 272
 273   /// Based on operator<
 274   template<typename _Tp, typename _Seq>
 275     inline bool
 276     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 277     { return __y < __x; }
 278
 279   /// Based on operator<
 280   template<typename _Tp, typename _Seq>
 281     inline bool
 282     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 283     { return !(__y < __x); }
 284
 285   /// Based on operator<
 286   template<typename _Tp, typename _Seq>
 287     inline bool
 288     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 289     { return !(__x < __y); }
 290
 291 #if __cplusplus >= 201103L
 292   template<typename _Tp, typename _Seq>
 293     inline void
 294     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 295     noexcept(noexcept(__x.swap(__y)))
 296     { __x.swap(__y); }
 297
 298   template<typename _Tp, typename _Seq, typename _Alloc>
 299     struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
 300     : public uses_allocator<_Seq, _Alloc>::type { };
 301 #endif
 302
 303 _GLIBCXX_END_NAMESPACE_VERSION
 304 } // namespace
 305
 306 #endif /* _STL_STACK_H */