freebsd-dev/contrib/libstdc++/include/bits/stl_stack.h
2004-07-28 03:12:05 +00:00

273 lines
9.2 KiB
C++

// Stack implementation -*- C++ -*-
// Copyright (C) 2001, 2002, 2004 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file stl_stack.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef _STACK_H
#define _STACK_H 1
#include <bits/concept_check.h>
#include <debug/debug.h>
namespace std
{
// Forward declarations of operators == and <, needed for friend
// declaration.
template<typename _Tp, typename _Sequence = deque<_Tp> >
class stack;
template<typename _Tp, typename _Seq>
inline bool
operator==(const stack<_Tp,_Seq>& __x, const stack<_Tp,_Seq>& __y);
template<typename _Tp, typename _Seq>
inline bool
operator<(const stack<_Tp,_Seq>& __x, const stack<_Tp,_Seq>& __y);
/**
* @brief A standard container giving FILO behavior.
*
* @ingroup Containers
* @ingroup Sequences
*
* Meets many of the requirements of a
* <a href="tables.html#65">container</a>,
* but does not define anything to do with iterators. Very few of the
* other standard container interfaces are defined.
*
* This is not a true container, but an @e adaptor. It holds
* another container, and provides a wrapper interface to that
* container. The wrapper is what enforces strict
* first-in-last-out %stack behavior.
*
* The second template parameter defines the type of the underlying
* sequence/container. It defaults to std::deque, but it can be
* any type that supports @c back, @c push_back, and @c pop_front,
* such as std::list, std::vector, or an appropriate user-defined
* type.
*
* Members not found in "normal" containers are @c container_type,
* which is a typedef for the second Sequence parameter, and @c
* push, @c pop, and @c top, which are standard %stack/FILO
* operations.
*/
template<typename _Tp, typename _Sequence>
class stack
{
// concept requirements
typedef typename _Sequence::value_type _Sequence_value_type;
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept)
__glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
template<typename _Tp1, typename _Seq1>
friend bool
operator==(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
template<typename _Tp1, typename _Seq1>
friend bool
operator<(const stack<_Tp1, _Seq1>&, const stack<_Tp1, _Seq1>&);
public:
typedef typename _Sequence::value_type value_type;
typedef typename _Sequence::reference reference;
typedef typename _Sequence::const_reference const_reference;
typedef typename _Sequence::size_type size_type;
typedef _Sequence container_type;
protected:
// See queue::c for notes on this name.
_Sequence c;
public:
// XXX removed old def ctor, added def arg to this one to match 14882
/**
* @brief Default constructor creates no elements.
*/
explicit
stack(const _Sequence& __c = _Sequence())
: c(__c) {}
/**
* Returns true if the %stack is empty.
*/
bool
empty() const
{ return c.empty(); }
/** Returns the number of elements in the %stack. */
size_type
size() const
{ return c.size(); }
/**
* Returns a read/write reference to the data at the first
* element of the %stack.
*/
reference
top()
{
__glibcxx_requires_nonempty();
return c.back();
}
/**
* Returns a read-only (constant) reference to the data at the first
* element of the %stack.
*/
const_reference
top() const
{
__glibcxx_requires_nonempty();
return c.back();
}
/**
* @brief Add data to the top of the %stack.
* @param x Data to be added.
*
* This is a typical %stack operation. The function creates an
* element at the top of the %stack and assigns the given data
* to it. The time complexity of the operation depends on the
* underlying sequence.
*/
void
push(const value_type& __x)
{ c.push_back(__x); }
/**
* @brief Removes first element.
*
* This is a typical %stack operation. It shrinks the %stack
* by one. The time complexity of the operation depends on the
* underlying sequence.
*
* Note that no data is returned, and if the first element's
* data is needed, it should be retrieved before pop() is
* called.
*/
void
pop()
{
__glibcxx_requires_nonempty();
c.pop_back();
}
};
/**
* @brief Stack equality comparison.
* @param x A %stack.
* @param y A %stack of the same type as @a x.
* @return True iff the size and elements of the stacks are equal.
*
* This is an equivalence relation. Complexity and semantics
* depend on the underlying sequence type, but the expected rules
* are: this relation is linear in the size of the sequences, and
* stacks are considered equivalent if their sequences compare
* equal.
*/
template<typename _Tp, typename _Seq>
inline bool
operator==(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __x.c == __y.c; }
/**
* @brief Stack ordering relation.
* @param x A %stack.
* @param y A %stack of the same type as @a x.
* @return True iff @a x is lexicographically less than @a y.
*
* This is an total ordering relation. Complexity and semantics
* depend on the underlying sequence type, but the expected rules
* are: this relation is linear in the size of the sequences, the
* elements must be comparable with @c <, and
* std::lexicographical_compare() is usually used to make the
* determination.
*/
template<typename _Tp, typename _Seq>
inline bool
operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __x.c < __y.c; }
/// Based on operator==
template<typename _Tp, typename _Seq>
inline bool
operator!=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return !(__x == __y); }
/// Based on operator<
template<typename _Tp, typename _Seq>
inline bool
operator>(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return __y < __x; }
/// Based on operator<
template<typename _Tp, typename _Seq>
inline bool
operator<=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return !(__y < __x); }
/// Based on operator<
template<typename _Tp, typename _Seq>
inline bool
operator>=(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
{ return !(__x < __y); }
} // namespace std
#endif /* _STACK_H */