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

   1 // Stack implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 /*
  27  *
  28  * Copyright (c) 1994
  29  * Hewlett-Packard Company
  30  *
  31  * Permission to use, copy, modify, distribute and sell this software
  32  * and its documentation for any purpose is hereby granted without fee,
  33  * provided that the above copyright notice appear in all copies and
  34  * that both that copyright notice and this permission notice appear
  35  * in supporting documentation.  Hewlett-Packard Company makes no
  36  * representations about the suitability of this software for any
  37  * purpose.  It is provided "as is" without express or implied warranty.
  38  *
  39  *
  40  * Copyright (c) 1996,1997
  41  * Silicon Graphics Computer Systems, Inc.
  42  *
  43  * Permission to use, copy, modify, distribute and sell this software
  44  * and its documentation for any purpose is hereby granted without fee,
  45  * provided that the above copyright notice appear in all copies and
  46  * that both that copyright notice and this permission notice appear
  47  * in supporting documentation.  Silicon Graphics makes no
  48  * representations about the suitability of this software for any
  49  * purpose.  It is provided "as is" without express or implied warranty.
  50  */
  51
  52 /** @file stl_stack.h
  53  *  This is an internal header file, included by other library headers.
  54  *  You should not attempt to use it directly.
  55  */
  56
  57 #ifndef _STL_STACK_H
  58 #define _STL_STACK_H 1
  59
  60 #include <bits/concept_check.h>
  61 #include <debug/debug.h>
  62
  63 _GLIBCXX_BEGIN_NAMESPACE(std)
  64
  65   /**
  66    *  @brief  A standard container giving FILO behavior.
  67    *
  68    *  @ingroup sequences
  69    *
  70    *  Meets many of the requirements of a
  71    *  <a href="tables.html#65">container</a>,
  72    *  but does not define anything to do with iterators.  Very few of the
  73    *  other standard container interfaces are defined.
  74    *
  75    *  This is not a true container, but an @e adaptor.  It holds
  76    *  another container, and provides a wrapper interface to that
  77    *  container.  The wrapper is what enforces strict
  78    *  first-in-last-out %stack behavior.
  79    *
  80    *  The second template parameter defines the type of the underlying
  81    *  sequence/container.  It defaults to std::deque, but it can be
  82    *  any type that supports @c back, @c push_back, and @c pop_front,
  83    *  such as std::list, std::vector, or an appropriate user-defined
  84    *  type.
  85    *
  86    *  Members not found in "normal" containers are @c container_type,
  87    *  which is a typedef for the second Sequence parameter, and @c
  88    *  push, @c pop, and @c top, which are standard %stack/FILO
  89    *  operations.
  90   */
  91   template<typename _Tp, typename _Sequence = deque<_Tp> >
  92     class stack
  93     {
  94       // concept requirements
  95       typedef typename _Sequence::value_type _Sequence_value_type;
  96       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
  97       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
  98       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
  99
 100       template<typename _Tp1, typename _Seq1>
 101         friend bool
 102         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 103
 104       template<typename _Tp1, typename _Seq1>
 105         friend bool
 106         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 107
 108     public:
 109       typedef typename _Sequence::value_type                value_type;
 110       typedef typename _Sequence::reference                 reference;
 111       typedef typename _Sequence::const_reference           const_reference;
 112       typedef typename _Sequence::size_type                 size_type;
 113       typedef          _Sequence                            container_type;
 114
 115     protected:
 116       //  See queue::c for notes on this name.
 117       _Sequence c;
 118
 119     public:
 120       // XXX removed old def ctor, added def arg to this one to match 14882
 121       /**
 122        *  @brief  Default constructor creates no elements.
 123        */
 124 #ifndef __GXX_EXPERIMENTAL_CXX0X__
 125       explicit
 126       stack(const _Sequence& __c = _Sequence())
 127       : c(__c) { }
 128 #else
 129       explicit
 130       stack(const _Sequence& __c)
 131       : c(__c) { }
 132
 133       explicit
 134       stack(_Sequence&& __c = _Sequence())
 135       : c(std::move(__c)) { }
 136 #endif
 137
 138       /**
 139        *  Returns true if the %stack is empty.
 140        */
 141       bool
 142       empty() const
 143       { return c.empty(); }
 144
 145       /**  Returns the number of elements in the %stack.  */
 146       size_type
 147       size() const
 148       { return c.size(); }
 149
 150       /**
 151        *  Returns a read/write reference to the data at the first
 152        *  element of the %stack.
 153        */
 154       reference
 155       top()
 156       {
 157         __glibcxx_requires_nonempty();
 158         return c.back();
 159       }
 160
 161       /**
 162        *  Returns a read-only (constant) reference to the data at the first
 163        *  element of the %stack.
 164        */
 165       const_reference
 166       top() const
 167       {
 168         __glibcxx_requires_nonempty();
 169         return c.back();
 170       }
 171
 172       /**
 173        *  @brief  Add data to the top of the %stack.
 174        *  @param  x  Data to be added.
 175        *
 176        *  This is a typical %stack operation.  The function creates an
 177        *  element at the top of the %stack and assigns the given data
 178        *  to it.  The time complexity of the operation depends on the
 179        *  underlying sequence.
 180        */
 181       void
 182       push(const value_type& __x)
 183       { c.push_back(__x); }
 184
 185 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 186       void
 187       push(value_type&& __x)
 188       { c.push_back(std::move(__x)); }
 189
 190       template<typename... _Args>
 191         void
 192         emplace(_Args&&... __args)
 193         { c.emplace_back(std::forward<_Args>(__args)...); }
 194 #endif
 195
 196       /**
 197        *  @brief  Removes first element.
 198        *
 199        *  This is a typical %stack operation.  It shrinks the %stack
 200        *  by one.  The time complexity of the operation depends on the
 201        *  underlying sequence.
 202        *
 203        *  Note that no data is returned, and if the first element's
 204        *  data is needed, it should be retrieved before pop() is
 205        *  called.
 206        */
 207       void
 208       pop()
 209       {
 210         __glibcxx_requires_nonempty();
 211         c.pop_back();
 212       }
 213
 214 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 215       void
 216       swap(stack& __s)
 217       { c.swap(__s.c); }
 218 #endif
 219     };
 220
 221   /**
 222    *  @brief  Stack equality comparison.
 223    *  @param  x  A %stack.
 224    *  @param  y  A %stack of the same type as @a x.
 225    *  @return  True iff the size and elements of the stacks are equal.
 226    *
 227    *  This is an equivalence relation.  Complexity and semantics
 228    *  depend on the underlying sequence type, but the expected rules
 229    *  are: this relation is linear in the size of the sequences, and
 230    *  stacks are considered equivalent if their sequences compare
 231    *  equal.
 232   */
 233   template<typename _Tp, typename _Seq>
 234     inline bool
 235     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 236     { return __x.c == __y.c; }
 237
 238   /**
 239    *  @brief  Stack ordering relation.
 240    *  @param  x  A %stack.
 241    *  @param  y  A %stack of the same type as @a x.
 242    *  @return  True iff @a x is lexicographically less than @a y.
 243    *
 244    *  This is an total ordering relation.  Complexity and semantics
 245    *  depend on the underlying sequence type, but the expected rules
 246    *  are: this relation is linear in the size of the sequences, the
 247    *  elements must be comparable with @c <, and
 248    *  std::lexicographical_compare() is usually used to make the
 249    *  determination.
 250   */
 251   template<typename _Tp, typename _Seq>
 252     inline bool
 253     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 254     { return __x.c < __y.c; }
 255
 256   /// Based on operator==
 257   template<typename _Tp, typename _Seq>
 258     inline bool
 259     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 260     { return !(__x == __y); }
 261
 262   /// Based on operator<
 263   template<typename _Tp, typename _Seq>
 264     inline bool
 265     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 266     { return __y < __x; }
 267
 268   /// Based on operator<
 269   template<typename _Tp, typename _Seq>
 270     inline bool
 271     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 272     { return !(__y < __x); }
 273
 274   /// Based on operator<
 275   template<typename _Tp, typename _Seq>
 276     inline bool
 277     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 278     { return !(__x < __y); }
 279
 280 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 281   template<typename _Tp, typename _Seq>
 282     inline void
 283     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 284     { __x.swap(__y); }
 285 #endif
 286
 287 _GLIBCXX_END_NAMESPACE
 288
 289 #endif /* _STL_STACK_H */