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 namespace std _GLIBCXX_VISIBILITY(default)
  65 {
  66 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  67
  68   /**
  69    *  @brief  A standard container giving FILO behavior.
  70    *
  71    *  @ingroup sequences
  72    *
  73    *  Meets many of the requirements of a
  74    *  <a href="tables.html#65">container</a>,
  75    *  but does not define anything to do with iterators.  Very few of the
  76    *  other standard container interfaces are defined.
  77    *
  78    *  This is not a true container, but an @e adaptor.  It holds
  79    *  another container, and provides a wrapper interface to that
  80    *  container.  The wrapper is what enforces strict
  81    *  first-in-last-out %stack behavior.
  82    *
  83    *  The second template parameter defines the type of the underlying
  84    *  sequence/container.  It defaults to std::deque, but it can be
  85    *  any type that supports @c back, @c push_back, and @c pop_front,
  86    *  such as std::list, std::vector, or an appropriate user-defined
  87    *  type.
  88    *
  89    *  Members not found in @a normal containers are @c container_type,
  90    *  which is a typedef for the second Sequence parameter, and @c
  91    *  push, @c pop, and @c top, which are standard %stack/FILO
  92    *  operations.
  93   */
  94   template<typename _Tp, typename _Sequence = deque<_Tp> >
  95     class stack
  96     {
  97       // concept requirements
  98       typedef typename _Sequence::value_type _Sequence_value_type;
  99       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
 100       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
 101       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
 102
 103       template<typename _Tp1, typename _Seq1>
 104         friend bool
 105         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 106
 107       template<typename _Tp1, typename _Seq1>
 108         friend bool
 109         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
 110
 111     public:
 112       typedef typename _Sequence::value_type                value_type;
 113       typedef typename _Sequence::reference                 reference;
 114       typedef typename _Sequence::const_reference           const_reference;
 115       typedef typename _Sequence::size_type                 size_type;
 116       typedef          _Sequence                            container_type;
 117
 118     protected:
 119       //  See queue::c for notes on this name.
 120       _Sequence c;
 121
 122     public:
 123       // XXX removed old def ctor, added def arg to this one to match 14882
 124       /**
 125        *  @brief  Default constructor creates no elements.
 126        */
 127 #ifndef __GXX_EXPERIMENTAL_CXX0X__
 128       explicit
 129       stack(const _Sequence& __c = _Sequence())
 130       : c(__c) { }
 131 #else
 132       explicit
 133       stack(const _Sequence& __c)
 134       : c(__c) { }
 135
 136       explicit
 137       stack(_Sequence&& __c = _Sequence())
 138       : c(std::move(__c)) { }
 139 #endif
 140
 141       /**
 142        *  Returns true if the %stack is empty.
 143        */
 144       bool
 145       empty() const
 146       { return c.empty(); }
 147
 148       /**  Returns the number of elements in the %stack.  */
 149       size_type
 150       size() const
 151       { return c.size(); }
 152
 153       /**
 154        *  Returns a read/write reference to the data at the first
 155        *  element of the %stack.
 156        */
 157       reference
 158       top()
 159       {
 160         __glibcxx_requires_nonempty();
 161         return c.back();
 162       }
 163
 164       /**
 165        *  Returns a read-only (constant) reference to the data at the first
 166        *  element of the %stack.
 167        */
 168       const_reference
 169       top() const
 170       {
 171         __glibcxx_requires_nonempty();
 172         return c.back();
 173       }
 174
 175       /**
 176        *  @brief  Add data to the top of the %stack.
 177        *  @param  __x  Data to be added.
 178        *
 179        *  This is a typical %stack operation.  The function creates an
 180        *  element at the top of the %stack and assigns the given data
 181        *  to it.  The time complexity of the operation depends on the
 182        *  underlying sequence.
 183        */
 184       void
 185       push(const value_type& __x)
 186       { c.push_back(__x); }
 187
 188 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 189       void
 190       push(value_type&& __x)
 191       { c.push_back(std::move(__x)); }
 192
 193       template<typename... _Args>
 194         void
 195         emplace(_Args&&... __args)
 196         { c.emplace_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       noexcept(noexcept(swap(c, __s.c)))
 221       {
 222         using std::swap;
 223         swap(c, __s.c);
 224       }
 225 #endif
 226     };
 227
 228   /**
 229    *  @brief  Stack equality comparison.
 230    *  @param  __x  A %stack.
 231    *  @param  __y  A %stack of the same type as @a __x.
 232    *  @return  True iff the size and elements of the stacks are equal.
 233    *
 234    *  This is an equivalence relation.  Complexity and semantics
 235    *  depend on the underlying sequence type, but the expected rules
 236    *  are: this relation is linear in the size of the sequences, and
 237    *  stacks are considered equivalent if their sequences compare
 238    *  equal.
 239   */
 240   template<typename _Tp, typename _Seq>
 241     inline bool
 242     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 243     { return __x.c == __y.c; }
 244
 245   /**
 246    *  @brief  Stack ordering relation.
 247    *  @param  __x  A %stack.
 248    *  @param  __y  A %stack of the same type as @a x.
 249    *  @return  True iff @a x is lexicographically less than @a __y.
 250    *
 251    *  This is an total ordering relation.  Complexity and semantics
 252    *  depend on the underlying sequence type, but the expected rules
 253    *  are: this relation is linear in the size of the sequences, the
 254    *  elements must be comparable with @c <, and
 255    *  std::lexicographical_compare() is usually used to make the
 256    *  determination.
 257   */
 258   template<typename _Tp, typename _Seq>
 259     inline bool
 260     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 261     { return __x.c < __y.c; }
 262
 263   /// Based on operator==
 264   template<typename _Tp, typename _Seq>
 265     inline bool
 266     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 267     { return !(__x == __y); }
 268
 269   /// Based on operator<
 270   template<typename _Tp, typename _Seq>
 271     inline bool
 272     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 273     { return __y < __x; }
 274
 275   /// Based on operator<
 276   template<typename _Tp, typename _Seq>
 277     inline bool
 278     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 279     { return !(__y < __x); }
 280
 281   /// Based on operator<
 282   template<typename _Tp, typename _Seq>
 283     inline bool
 284     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 285     { return !(__x < __y); }
 286
 287 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 288   template<typename _Tp, typename _Seq>
 289     inline void
 290     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 291     noexcept(noexcept(__x.swap(__y)))
 292     { __x.swap(__y); }
 293
 294   template<typename _Tp, typename _Seq, typename _Alloc>
 295     struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
 296     : public uses_allocator<_Seq, _Alloc>::type { };
 297 #endif
 298
 299 _GLIBCXX_END_NAMESPACE_VERSION
 300 } // namespace
 301
 302 #endif /* _STL_STACK_H */