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, 2012
   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    *  @tparam _Tp  Type of element.
  74    *  @tparam _Sequence  Type of underlying sequence, defaults to deque<_Tp>.
  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 @a 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       void
 188       push(const value_type& __x)
 189       { c.push_back(__x); }
 190
 191 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 192       void
 193       push(value_type&& __x)
 194       { c.push_back(std::move(__x)); }
 195
 196       template<typename... _Args>
 197         void
 198         emplace(_Args&&... __args)
 199         { c.emplace_back(std::forward<_Args>(__args)...); }
 200 #endif
 201
 202       /**
 203        *  @brief  Removes first element.
 204        *
 205        *  This is a typical %stack operation.  It shrinks the %stack
 206        *  by one.  The time complexity of the operation depends on the
 207        *  underlying sequence.
 208        *
 209        *  Note that no data is returned, and if the first element's
 210        *  data is needed, it should be retrieved before pop() is
 211        *  called.
 212        */
 213       void
 214       pop()
 215       {
 216         __glibcxx_requires_nonempty();
 217         c.pop_back();
 218       }
 219
 220 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 221       void
 222       swap(stack& __s)
 223       noexcept(noexcept(swap(c, __s.c)))
 224       {
 225         using std::swap;
 226         swap(c, __s.c);
 227       }
 228 #endif
 229     };
 230
 231   /**
 232    *  @brief  Stack equality comparison.
 233    *  @param  __x  A %stack.
 234    *  @param  __y  A %stack of the same type as @a __x.
 235    *  @return  True iff the size and elements of the stacks are equal.
 236    *
 237    *  This is an equivalence relation.  Complexity and semantics
 238    *  depend on the underlying sequence type, but the expected rules
 239    *  are: this relation is linear in the size of the sequences, and
 240    *  stacks are considered equivalent if their sequences compare
 241    *  equal.
 242   */
 243   template<typename _Tp, typename _Seq>
 244     inline bool
 245     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 246     { return __x.c == __y.c; }
 247
 248   /**
 249    *  @brief  Stack ordering relation.
 250    *  @param  __x  A %stack.
 251    *  @param  __y  A %stack of the same type as @a x.
 252    *  @return  True iff @a x is lexicographically less than @a __y.
 253    *
 254    *  This is an total ordering relation.  Complexity and semantics
 255    *  depend on the underlying sequence type, but the expected rules
 256    *  are: this relation is linear in the size of the sequences, the
 257    *  elements must be comparable with @c <, and
 258    *  std::lexicographical_compare() is usually used to make the
 259    *  determination.
 260   */
 261   template<typename _Tp, typename _Seq>
 262     inline bool
 263     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 264     { return __x.c < __y.c; }
 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 !(__x == __y); }
 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 !(__y < __x); }
 283
 284   /// Based on operator<
 285   template<typename _Tp, typename _Seq>
 286     inline bool
 287     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
 288     { return !(__x < __y); }
 289
 290 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 291   template<typename _Tp, typename _Seq>
 292     inline void
 293     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
 294     noexcept(noexcept(__x.swap(__y)))
 295     { __x.swap(__y); }
 296
 297   template<typename _Tp, typename _Seq, typename _Alloc>
 298     struct uses_allocator<stack<_Tp, _Seq>, _Alloc>
 299     : public uses_allocator<_Seq, _Alloc>::type { };
 300 #endif
 301
 302 _GLIBCXX_END_NAMESPACE_VERSION
 303 } // namespace
 304
 305 #endif /* _STL_STACK_H */