# stl_stack.h

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    00001 // Stack implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 /*
    00032  *
    00033  * Copyright (c) 1994
    00034  * Hewlett-Packard Company
    00035  *
    00036  * Permission to use, copy, modify, distribute and sell this software
    00037  * and its documentation for any purpose is hereby granted without fee,
    00038  * provided that the above copyright notice appear in all copies and
    00039  * that both that copyright notice and this permission notice appear
    00040  * in supporting documentation.  Hewlett-Packard Company makes no
    00041  * representations about the suitability of this software for any
    00042  * purpose.  It is provided "as is" without express or implied warranty.
    00043  *
    00044  *
    00045  * Copyright (c) 1996,1997
    00046  * Silicon Graphics Computer Systems, Inc.
    00047  *
    00048  * Permission to use, copy, modify, distribute and sell this software
    00049  * and its documentation for any purpose is hereby granted without fee,
    00050  * provided that the above copyright notice appear in all copies and
    00051  * that both that copyright notice and this permission notice appear
    00052  * in supporting documentation.  Silicon Graphics makes no
    00053  * representations about the suitability of this software for any
    00054  * purpose.  It is provided "as is" without express or implied warranty.
    00055  */
    00056
    00057 /** @file stl_stack.h
    00058  *  This is an internal header file, included by other library headers.
    00059  *  You should not attempt to use it directly.
    00060  */
    00061
    00062 #ifndef _STL_STACK_H
    00063 #define _STL_STACK_H 1
    00064
    00065 #include <bits/concept_check.h>
    00066 #include <debug/debug.h>
    00067
    00068 _GLIBCXX_BEGIN_NAMESPACE(std)
    00069
    00070   /**
    00071    *  @brief  A standard container giving FILO behavior.
    00072    *
    00073    *  @ingroup Containers
    00074    *  @ingroup Sequences
    00075    *
    00076    *  Meets many of the requirements of a
    00077    *  <a href="tables.html#65">container</a>,
    00078    *  but does not define anything to do with iterators.  Very few of the
    00079    *  other standard container interfaces are defined.
    00080    *
    00081    *  This is not a true container, but an @e adaptor.  It holds
    00082    *  another container, and provides a wrapper interface to that
    00083    *  container.  The wrapper is what enforces strict
    00084    *  first-in-last-out %stack behavior.
    00085    *
    00086    *  The second template parameter defines the type of the underlying
    00087    *  sequence/container.  It defaults to std::deque, but it can be
    00088    *  any type that supports @c back, @c push_back, and @c pop_front,
    00089    *  such as std::list, std::vector, or an appropriate user-defined
    00090    *  type.
    00091    *
    00092    *  Members not found in "normal" containers are @c container_type,
    00093    *  which is a typedef for the second Sequence parameter, and @c
    00094    *  push, @c pop, and @c top, which are standard %stack/FILO
    00095    *  operations.
    00096   */
    00097   template<typename _Tp, typename _Sequence = deque<_Tp> >
    00098     class stack
    00099     {
    00100       // concept requirements
    00101       typedef typename _Sequence::value_type _Sequence_value_type;
    00102       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
    00103       __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
    00104       __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
    00105
    00106       template<typename _Tp1, typename _Seq1>
    00107         friend bool
    00108         operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
    00109
    00110       template<typename _Tp1, typename _Seq1>
    00111         friend bool
    00112         operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
    00113
    00114     public:
    00115       typedef typename _Sequence::value_type                value_type;
    00116       typedef typename _Sequence::reference                 reference;
    00117       typedef typename _Sequence::const_reference           const_reference;
    00118       typedef typename _Sequence::size_type                 size_type;
    00119       typedef          _Sequence                            container_type;
    00120
    00121     protected:
    00122       //  See queue::c for notes on this name.
    00123       _Sequence c;
    00124
    00125     public:
    00126       // XXX removed old def ctor, added def arg to this one to match 14882
    00127       /**
    00128        *  @brief  Default constructor creates no elements.
    00129        */
    00130 #ifndef __GXX_EXPERIMENTAL_CXX0X__
    00131       explicit
    00132       stack(const _Sequence& __c = _Sequence())
    00133       : c(__c) { }
    00134 #else
    00135       explicit
    00136       stack(const _Sequence& __c)
    00137       : c(__c) { }
    00138
    00139       explicit
    00140       stack(_Sequence&& __c = _Sequence())
    00141       : c(std::move(__c)) { }
    00142 #endif
    00143
    00144       /**
    00145        *  Returns true if the %stack is empty.
    00146        */
    00147       bool
    00148       empty() const
    00149       { return c.empty(); }
    00150
    00151       /**  Returns the number of elements in the %stack.  */
    00152       size_type
    00153       size() const
    00154       { return c.size(); }
    00155
    00156       /**
    00157        *  Returns a read/write reference to the data at the first
    00158        *  element of the %stack.
    00159        */
    00160       reference
    00161       top()
    00162       {
    00163     __glibcxx_requires_nonempty();
    00164     return c.back();
    00165       }
    00166
    00167       /**
    00168        *  Returns a read-only (constant) reference to the data at the first
    00169        *  element of the %stack.
    00170        */
    00171       const_reference
    00172       top() const
    00173       {
    00174     __glibcxx_requires_nonempty();
    00175     return c.back();
    00176       }
    00177
    00178       /**
    00179        *  @brief  Add data to the top of the %stack.
    00180        *  @param  x  Data to be added.
    00181        *
    00182        *  This is a typical %stack operation.  The function creates an
    00183        *  element at the top of the %stack and assigns the given data
    00184        *  to it.  The time complexity of the operation depends on the
    00185        *  underlying sequence.
    00186        */
    00187 #ifndef __GXX_EXPERIMENTAL_CXX0X__
    00188       void
    00189       push(const value_type& __x)
    00190       { c.push_back(__x); }
    00191 #else
    00192       // NB: DR 756.
    00193       template<typename... _Args>
    00194         void
    00195         push(_Args&&... __args)
    00196     { c.push_back(std::forward<_Args>(__args)...); }
    00197 #endif
    00198
    00199       /**
    00200        *  @brief  Removes first element.
    00201        *
    00202        *  This is a typical %stack operation.  It shrinks the %stack
    00203        *  by one.  The time complexity of the operation depends on the
    00204        *  underlying sequence.
    00205        *
    00206        *  Note that no data is returned, and if the first element's
    00207        *  data is needed, it should be retrieved before pop() is
    00208        *  called.
    00209        */
    00210       void
    00211       pop()
    00212       {
    00213     __glibcxx_requires_nonempty();
    00214     c.pop_back();
    00215       }
    00216
    00217 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    00218       void
    00219       swap(stack&& __s)
    00220       { c.swap(__s.c); }
    00221 #endif
    00222     };
    00223
    00224   /**
    00225    *  @brief  Stack equality comparison.
    00226    *  @param  x  A %stack.
    00227    *  @param  y  A %stack of the same type as @a x.
    00228    *  @return  True iff the size and elements of the stacks are equal.
    00229    *
    00230    *  This is an equivalence relation.  Complexity and semantics
    00231    *  depend on the underlying sequence type, but the expected rules
    00232    *  are: this relation is linear in the size of the sequences, and
    00233    *  stacks are considered equivalent if their sequences compare
    00234    *  equal.
    00235   */
    00236   template<typename _Tp, typename _Seq>
    00237     inline bool
    00238     operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
    00239     { return __x.c == __y.c; }
    00240
    00241   /**
    00242    *  @brief  Stack ordering relation.
    00243    *  @param  x  A %stack.
    00244    *  @param  y  A %stack of the same type as @a x.
    00245    *  @return  True iff @a x is lexicographically less than @a y.
    00246    *
    00247    *  This is an total ordering relation.  Complexity and semantics
    00248    *  depend on the underlying sequence type, but the expected rules
    00249    *  are: this relation is linear in the size of the sequences, the
    00250    *  elements must be comparable with @c <, and
    00251    *  std::lexicographical_compare() is usually used to make the
    00252    *  determination.
    00253   */
    00254   template<typename _Tp, typename _Seq>
    00255     inline bool
    00256     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
    00257     { return __x.c < __y.c; }
    00258
    00259   /// Based on operator==
    00260   template<typename _Tp, typename _Seq>
    00261     inline bool
    00262     operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
    00263     { return !(__x == __y); }
    00264
    00265   /// Based on operator<
    00266   template<typename _Tp, typename _Seq>
    00267     inline bool
    00268     operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
    00269     { return __y < __x; }
    00270
    00271   /// Based on operator<
    00272   template<typename _Tp, typename _Seq>
    00273     inline bool
    00274     operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
    00275     { return !(__y < __x); }
    00276
    00277   /// Based on operator<
    00278   template<typename _Tp, typename _Seq>
    00279     inline bool
    00280     operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
    00281     { return !(__x < __y); }
    00282
    00283 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    00284   template<typename _Tp, typename _Seq>
    00285     inline void
    00286     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>& __y)
    00287     { __x.swap(__y); }
    00288
    00289   template<typename _Tp, typename _Seq>
    00290     inline void
    00291     swap(stack<_Tp, _Seq>&& __x, stack<_Tp, _Seq>& __y)
    00292     { __x.swap(__y); }
    00293
    00294   template<typename _Tp, typename _Seq>
    00295     inline void
    00296     swap(stack<_Tp, _Seq>& __x, stack<_Tp, _Seq>&& __y)
    00297     { __x.swap(__y); }
    00298 #endif
    00299
    00300 _GLIBCXX_END_NAMESPACE
    00301
    00302 #endif /* _STL_STACK_H */