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 // 2010, 2011
   5 // Free Software Foundation, Inc.
   6 //
   7 // This file is part of the GNU ISO C++ Library.  This library is free
   8 // software; you can redistribute it and/or modify it under the
   9 // terms of the GNU General Public License as published by the
  10 // Free Software Foundation; either version 3, or (at your option)
  11 // any later version.
  12
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // Under Section 7 of GPL version 3, you are granted additional
  19 // permissions described in the GCC Runtime Library Exception, version
  20 // 3.1, as published by the Free Software Foundation.
  21
  22 // You should have received a copy of the GNU General Public License and
  23 // a copy of the GCC Runtime Library Exception along with this program;
  24 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 // <http://www.gnu.org/licenses/>.
  26
  27 /*
  28  *
  29  * Copyright (c) 1994
  30  * Hewlett-Packard Company
  31  *
  32  * Permission to use, copy, modify, distribute and sell this software
  33  * and its documentation for any purpose is hereby granted without fee,
  34  * provided that the above copyright notice appear in all copies and
  35  * that both that copyright notice and this permission notice appear
  36  * in supporting documentation.  Hewlett-Packard Company makes no
  37  * representations about the suitability of this software for any
  38  * purpose.  It is provided "as is" without express or implied warranty.
  39  *
  40  *
  41  * Copyright (c) 1996,1997
  42  * Silicon Graphics Computer Systems, Inc.
  43  *
  44  * Permission to use, copy, modify, distribute and sell this software
  45  * and its documentation for any purpose is hereby granted without fee,
  46  * provided that the above copyright notice appear in all copies and
  47  * that both that copyright notice and this permission notice appear
  48  * in supporting documentation.  Silicon Graphics makes no
  49  * representations about the suitability of this software for any
  50  * purpose.  It is provided "as is" without express or implied warranty.
  51  */
  52
  53 /** @file bits/stl_stack.h
  54  *  This is an internal header file, included by other library headers.
  55  *  Do not attempt to use it directly. @headername{stack}
  56  */
  57
  58 #ifndef _STL_STACK_H
  59 #define _STL_STACK_H 1
  60
  61 #include <bits/concept_check.h>
  62 #include <debug/debug.h>
  63
  64 _GLIBCXX_BEGIN_NAMESPACE(std)
  65
  66   /**
  67    *  @brief  A standard container giving FILO behavior.
  68    *
  69    *  @ingroup sequences
  70    *
  71    *  Meets many of the requirements of a
  72    *  <a href="tables.html#65">container</a>,
  73    *  but does not define anything to do with iterators.  Very few of the
  74    *  other standard container interfaces are defined.
  75    *
  76    *  This is not a true container, but an @e adaptor.  It holds
  77    *  another container, and provides a wrapper interface to that
  78    *  container.  The wrapper is what enforces strict
  79    *  first-in-last-out %stack behavior.
  80    *
  81    *  The second template parameter defines the type of the underlying
  82    *  sequence/container.  It defaults to std::deque, but it can be
  83    *  any type that supports @c back, @c push_back, and @c pop_front,
  84    *  such as std::list, std::vector, or an appropriate user-defined
  85    *  type.
  86    *
  87    *  Members not found in @a normal containers are @c container_type,
  88    *  which is a typedef for the second Sequence parameter, and @c
  89    *  push, @c pop, and @c top, which are standard %stack/FILO
  90    *  operations.
  91   */
  92   template<typename _Tp, typename _Sequence = deque<_Tp> >
  93     class stack
  94     {
  95       // concept requirements
  96       typedef typename _Sequence::value_type _Sequence_value_type;
  97       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
  98       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
  99       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
 100
 101       template<typename _Tp1, typename _Seq1>
 102         friend bool
 103         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 104
 105       template<typename _Tp1, typename _Seq1>
 106         friend bool
 107         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 108
 109     public:
 110       typedef typename _Sequence::value_type                value_type;
 111       typedef typename _Sequence::reference                 reference;
 112       typedef typename _Sequence::const_reference           const_reference;
 113       typedef typename _Sequence::size_type                 size_type;
 114       typedef          _Sequence                            container_type;
 115
 116     protected:
 117       //  See queue::c for notes on this name.
 118       _Sequence c;
 119
 120     public:
 121       // XXX removed old def ctor, added def arg to this one to match 14882
 122       /**
 123        *  @brief  Default constructor creates no elements.
 124        */
 125 #ifndef __GXX_EXPERIMENTAL_CXX0X__
 126       explicit
 127       stack(const _Sequence& __c = _Sequence())
 128       : c(__c) { }
 129 #else
 130       explicit
 131       stack(const _Sequence& __c)
 132       : c(__c) { }
 133
 134       explicit
 135       stack(_Sequence&& __c = _Sequence())
 136       : c(std::move(__c)) { }
 137 #endif
 138
 139       /**
 140        *  Returns true if the %stack is empty.
 141        */
 142       bool
 143       empty() const
 144       { return c.empty(); }
 145
 146       /**  Returns the number of elements in the %stack.  */
 147       size_type
 148       size() const
 149       { return c.size(); }
 150
 151       /**
 152        *  Returns a read/write reference to the data at the first
 153        *  element of the %stack.
 154        */
 155       reference
 156       top()
 157       {
 158         __glibcxx_requires_nonempty();
 159         return c.back();
 160       }
 161
 162       /**
 163        *  Returns a read-only (constant) reference to the data at the first
 164        *  element of the %stack.
 165        */
 166       const_reference
 167       top() const
 168       {
 169         __glibcxx_requires_nonempty();
 170         return c.back();
 171       }
 172
 173       /**
 174        *  @brief  Add data to the top of the %stack.
 175        *  @param  x  Data to be added.
 176        *
 177        *  This is a typical %stack operation.  The function creates an
 178        *  element at the top of the %stack and assigns the given data
 179        *  to it.  The time complexity of the operation depends on the
 180        *  underlying sequence.
 181        */
 182       void
 183       push(const value_type& __x)
 184       { c.push_back(__x); }
 185
 186 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 187       void
 188       push(value_type&& __x)
 189       { c.push_back(std::move(__x)); }
 190
 191       template<typename... _Args>
 192         void
 193         emplace(_Args&&... __args)
 194         { c.emplace_back(std::forward<_Args>(__args)...); }
 195 #endif
 196
 197       /**
 198        *  @brief  Removes first element.
 199        *
 200        *  This is a typical %stack operation.  It shrinks the %stack
 201        *  by one.  The time complexity of the operation depends on the
 202        *  underlying sequence.
 203        *
 204        *  Note that no data is returned, and if the first element's
 205        *  data is needed, it should be retrieved before pop() is
 206        *  called.
 207        */
 208       void
 209       pop()
 210       {
 211         __glibcxx_requires_nonempty();
 212         c.pop_back();
 213       }
 214
 215 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 216       void
 217       swap(stack& __s)
 218       {
 219         using std::swap;
 220         swap(c, __s.c);
 221       }
 222 #endif
 223     };
 224
 225   /**
 226    *  @brief  Stack equality comparison.
 227    *  @param  x  A %stack.
 228    *  @param  y  A %stack of the same type as @a x.
 229    *  @return  True iff the size and elements of the stacks are equal.
 230    *
 231    *  This is an equivalence relation.  Complexity and semantics
 232    *  depend on the underlying sequence type, but the expected rules
 233    *  are: this relation is linear in the size of the sequences, and
 234    *  stacks are considered equivalent if their sequences compare
 235    *  equal.
 236   */
 237   template<typename _Tp, typename _Seq>
 238     inline bool
 239     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 240     { return __x.c == __y.c; }
 241
 242   /**
 243    *  @brief  Stack ordering relation.
 244    *  @param  x  A %stack.
 245    *  @param  y  A %stack of the same type as @a x.
 246    *  @return  True iff @a x is lexicographically less than @a y.
 247    *
 248    *  This is an total ordering relation.  Complexity and semantics
 249    *  depend on the underlying sequence type, but the expected rules
 250    *  are: this relation is linear in the size of the sequences, the
 251    *  elements must be comparable with @c <, and
 252    *  std::lexicographical_compare() is usually used to make the
 253    *  determination.
 254   */
 255   template<typename _Tp, typename _Seq>
 256     inline bool
 257     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 258     { return __x.c < __y.c; }
 259
 260   /// Based on operator==
 261   template<typename _Tp, typename _Seq>
 262     inline bool
 263     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 264     { return !(__x == __y); }
 265
 266   /// Based on operator<
 267   template<typename _Tp, typename _Seq>
 268     inline bool
 269     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 270     { return __y < __x; }
 271
 272   /// Based on operator<
 273   template<typename _Tp, typename _Seq>
 274     inline bool
 275     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 276     { return !(__y < __x); }
 277
 278   /// Based on operator<
 279   template<typename _Tp, typename _Seq>
 280     inline bool
 281     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 282     { return !(__x < __y); }
 283
 284 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 285   template<typename _Tp, typename _Seq>
 286     inline void
 287     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 288     { __x.swap(__y); }
 289
 290   template<typename _Tp, typename _Seq, typename _Alloc>
 291     struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
 292     : public uses_allocator<_Seq, _Alloc>::type { };
 293 #endif
 294
 295 _GLIBCXX_END_NAMESPACE
 296
 297 #endif /* _STL_STACK_H */