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

   1 // Stack implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /*
  32  *
  33  * Copyright (c) 1994
  34  * Hewlett-Packard Company
  35  *
  36  * Permission to use, copy, modify, distribute and sell this software
  37  * and its documentation for any purpose is hereby granted without fee,
  38  * provided that the above copyright notice appear in all copies and
  39  * that both that copyright notice and this permission notice appear
  40  * in supporting documentation.  Hewlett-Packard Company makes no
  41  * representations about the suitability of this software for any
  42  * purpose.  It is provided "as is" without express or implied warranty.
  43  *
  44  *
  45  * Copyright (c) 1996,1997
  46  * Silicon Graphics Computer Systems, Inc.
  47  *
  48  * Permission to use, copy, modify, distribute and sell this software
  49  * and its documentation for any purpose is hereby granted without fee,
  50  * provided that the above copyright notice appear in all copies and
  51  * that both that copyright notice and this permission notice appear
  52  * in supporting documentation.  Silicon Graphics makes no
  53  * representations about the suitability of this software for any
  54  * purpose.  It is provided "as is" without express or implied warranty.
  55  */
  56
  57 /** @file stl_stack.h
  58  *  This is an internal header file, included by other library headers.
  59  *  You should not attempt to use it directly.
  60  */
  61
  62 #ifndef _STL_STACK_H
  63 #define _STL_STACK_H 1
  64
  65 #include <bits/concept_check.h>
  66 #include <debug/debug.h>
  67
  68 _GLIBCXX_BEGIN_NAMESPACE(std)
  69
  70   /**
  71    *  @brief  A standard container giving FILO behavior.
  72    *
  73    *  @ingroup Containers
  74    *  @ingroup Sequences
  75    *
  76    *  Meets many of the requirements of a
  77    *  <a href="tables.html#65">container</a>,
  78    *  but does not define anything to do with iterators.  Very few of the
  79    *  other standard container interfaces are defined.
  80    *
  81    *  This is not a true container, but an @e adaptor.  It holds
  82    *  another container, and provides a wrapper interface to that
  83    *  container.  The wrapper is what enforces strict
  84    *  first-in-last-out %stack behavior.
  85    *
  86    *  The second template parameter defines the type of the underlying
  87    *  sequence/container.  It defaults to std::deque, but it can be
  88    *  any type that supports @c back, @c push_back, and @c pop_front,
  89    *  such as std::list, std::vector, or an appropriate user-defined
  90    *  type.
  91    *
  92    *  Members not found in "normal" containers are @c container_type,
  93    *  which is a typedef for the second Sequence parameter, and @c
  94    *  push, @c pop, and @c top, which are standard %stack/FILO
  95    *  operations.
  96   */
  97   template<typename _Tp, typename _Sequence = deque<_Tp> >
  98     class stack
  99     {
 100       // concept requirements
 101       typedef typename _Sequence::value_type _Sequence_value_type;
 102       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
 103       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
 104       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
 105
 106       template<typename _Tp1, typename _Seq1>
 107         friend bool
 108         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 109
 110       template<typename _Tp1, typename _Seq1>
 111         friend bool
 112         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 113
 114     public:
 115       typedef typename _Sequence::value_type                value_type;
 116       typedef typename _Sequence::reference                 reference;
 117       typedef typename _Sequence::const_reference           const_reference;
 118       typedef typename _Sequence::size_type                 size_type;
 119       typedef          _Sequence                            container_type;
 120
 121     protected:
 122       //  See queue::c for notes on this name.
 123       _Sequence c;
 124
 125     public:
 126       // XXX removed old def ctor, added def arg to this one to match 14882
 127       /**
 128        *  @brief  Default constructor creates no elements.
 129        */
 130 #ifndef __GXX_EXPERIMENTAL_CXX0X__
 131       explicit
 132       stack(const _Sequence& __c = _Sequence())
 133       : c(__c) { }
 134 #else
 135       explicit
 136       stack(const _Sequence& __c)
 137       : c(__c) { }
 138
 139       explicit
 140       stack(_Sequence&& __c = _Sequence())
 141       : c(std::move(__c)) { }
 142 #endif
 143
 144       /**
 145        *  Returns true if the %stack is empty.
 146        */
 147       bool
 148       empty() const
 149       { return c.empty(); }
 150
 151       /**  Returns the number of elements in the %stack.  */
 152       size_type
 153       size() const
 154       { return c.size(); }
 155
 156       /**
 157        *  Returns a read/write reference to the data at the first
 158        *  element of the %stack.
 159        */
 160       reference
 161       top()
 162       {
 163         __glibcxx_requires_nonempty();
 164         return c.back();
 165       }
 166
 167       /**
 168        *  Returns a read-only (constant) reference to the data at the first
 169        *  element of the %stack.
 170        */
 171       const_reference
 172       top() const
 173       {
 174         __glibcxx_requires_nonempty();
 175         return c.back();
 176       }
 177
 178       /**
 179        *  @brief  Add data to the top of the %stack.
 180        *  @param  x  Data to be added.
 181        *
 182        *  This is a typical %stack operation.  The function creates an
 183        *  element at the top of the %stack and assigns the given data
 184        *  to it.  The time complexity of the operation depends on the
 185        *  underlying sequence.
 186        */
 187 #ifndef __GXX_EXPERIMENTAL_CXX0X__
 188       void
 189       push(const value_type& __x)
 190       { c.push_back(__x); }
 191 #else
 192       // NB: DR 756.
 193       template<typename... _Args>
 194         void
 195         push(_Args&&... __args)
 196         { c.push_back(std::forward<_Args>(__args)...); }
 197 #endif
 198
 199       /**
 200        *  @brief  Removes first element.
 201        *
 202        *  This is a typical %stack operation.  It shrinks the %stack
 203        *  by one.  The time complexity of the operation depends on the
 204        *  underlying sequence.
 205        *
 206        *  Note that no data is returned, and if the first element's
 207        *  data is needed, it should be retrieved before pop() is
 208        *  called.
 209        */
 210       void
 211       pop()
 212       {
 213         __glibcxx_requires_nonempty();
 214         c.pop_back();
 215       }
 216
 217 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 218       void
 219       swap(stack&& __s)
 220       { c.swap(__s.c); }
 221 #endif
 222     };
 223
 224   /**
 225    *  @brief  Stack equality comparison.
 226    *  @param  x  A %stack.
 227    *  @param  y  A %stack of the same type as @a x.
 228    *  @return  True iff the size and elements of the stacks are equal.
 229    *
 230    *  This is an equivalence relation.  Complexity and semantics
 231    *  depend on the underlying sequence type, but the expected rules
 232    *  are: this relation is linear in the size of the sequences, and
 233    *  stacks are considered equivalent if their sequences compare
 234    *  equal.
 235   */
 236   template<typename _Tp, typename _Seq>
 237     inline bool
 238     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 239     { return __x.c == __y.c; }
 240
 241   /**
 242    *  @brief  Stack ordering relation.
 243    *  @param  x  A %stack.
 244    *  @param  y  A %stack of the same type as @a x.
 245    *  @return  True iff @a x is lexicographically less than @a y.
 246    *
 247    *  This is an total ordering relation.  Complexity and semantics
 248    *  depend on the underlying sequence type, but the expected rules
 249    *  are: this relation is linear in the size of the sequences, the
 250    *  elements must be comparable with @c <, and
 251    *  std::lexicographical_compare() is usually used to make the
 252    *  determination.
 253   */
 254   template<typename _Tp, typename _Seq>
 255     inline bool
 256     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 257     { return __x.c < __y.c; }
 258
 259   /// Based on operator==
 260   template<typename _Tp, typename _Seq>
 261     inline bool
 262     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 263     { return !(__x == __y); }
 264
 265   /// Based on operator<
 266   template<typename _Tp, typename _Seq>
 267     inline bool
 268     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 269     { return __y < __x; }
 270
 271   /// Based on operator<
 272   template<typename _Tp, typename _Seq>
 273     inline bool
 274     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 275     { return !(__y < __x); }
 276
 277   /// Based on operator<
 278   template<typename _Tp, typename _Seq>
 279     inline bool
 280     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 281     { return !(__x < __y); }
 282
 283 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 284   template<typename _Tp, typename _Seq>
 285     inline void
 286     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 287     { __x.swap(__y); }
 288
 289   template<typename _Tp, typename _Seq>
 290     inline void
 291     swap(stack<_Tp, _Seq>&& __x, stack<_Tp, _Seq>& __y)
 292     { __x.swap(__y); }
 293
 294   template<typename _Tp, typename _Seq>
 295     inline void
 296     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>&& __y)
 297     { __x.swap(__y); }
 298 #endif
 299
 300 _GLIBCXX_END_NAMESPACE
 301
 302 #endif /* _STL_STACK_H */