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// Iterators -*- C++ -*-
// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
// 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// 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) 1996-1998
* 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_iterator.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*
* This file implements reverse_iterator, back_insert_iterator,
* front_insert_iterator, insert_iterator, __normal_iterator, and their
* supporting functions and overloaded operators.
*/
#ifndef _ITERATOR_H
#define _ITERATOR_H 1
#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>
_GLIBCXX_BEGIN_NAMESPACE(std)
// 24.4.1 Reverse iterators
/**
* "Bidirectional and random access iterators have corresponding reverse
* %iterator adaptors that iterate through the data structure in the
* opposite direction. They have the same signatures as the corresponding
* iterators. The fundamental relation between a reverse %iterator and its
* corresponding %iterator @c i is established by the identity:
* @code
* &*(reverse_iterator(i)) == &*(i - 1)
* @endcode
*
* This mapping is dictated by the fact that while there is always a
* pointer past the end of an array, there might not be a valid pointer
* before the beginning of an array." [24.4.1]/1,2
*
* Reverse iterators can be tricky and surprising at first. Their
* semantics make sense, however, and the trickiness is a side effect of
* the requirement that the iterators must be safe.
*/
template<typename _Iterator>
class reverse_iterator
: public iterator<typename iterator_traits<_Iterator>::iterator_category,
typename iterator_traits<_Iterator>::value_type,
typename iterator_traits<_Iterator>::difference_type,
typename iterator_traits<_Iterator>::pointer,
typename iterator_traits<_Iterator>::reference>
{
protected:
_Iterator current;
public:
typedef _Iterator iterator_type;
typedef typename iterator_traits<_Iterator>::difference_type
difference_type;
typedef typename iterator_traits<_Iterator>::reference reference;
typedef typename iterator_traits<_Iterator>::pointer pointer;
public:
/**
* The default constructor default-initializes member @p current.
* If it is a pointer, that means it is zero-initialized.
*/
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 235 No specification of default ctor for reverse_iterator
reverse_iterator() : current() { }
/**
* This %iterator will move in the opposite direction that @p x does.
*/
explicit
reverse_iterator(iterator_type __x) : current(__x) { }
/**
* The copy constructor is normal.
*/
reverse_iterator(const reverse_iterator& __x)
: current(__x.current) { }
/**
* A reverse_iterator across other types can be copied in the normal
* fashion.
*/
template<typename _Iter>
reverse_iterator(const reverse_iterator<_Iter>& __x)
: current(__x.base()) { }
/**
* @return @c current, the %iterator used for underlying work.
*/
iterator_type
base() const
{ return current; }
/**
* @return TODO
*
* @doctodo
*/
reference
operator*() const
{
_Iterator __tmp = current;
return *--__tmp;
}
/**
* @return TODO
*
* @doctodo
*/
pointer
operator->() const
{ return &(operator*()); }
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator&
operator++()
{
--current;
return *this;
}
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator
operator++(int)
{
reverse_iterator __tmp = *this;
--current;
return __tmp;
}
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator&
operator--()
{
++current;
return *this;
}
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator
operator--(int)
{
reverse_iterator __tmp = *this;
++current;
return __tmp;
}
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator
operator+(difference_type __n) const
{ return reverse_iterator(current - __n); }
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator&
operator+=(difference_type __n)
{
current -= __n;
return *this;
}
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator
operator-(difference_type __n) const
{ return reverse_iterator(current + __n); }
/**
* @return TODO
*
* @doctodo
*/
reverse_iterator&
operator-=(difference_type __n)
{
current += __n;
return *this;
}
/**
* @return TODO
*
* @doctodo
*/
reference
operator[](difference_type __n) const
{ return *(*this + __n); }
};
//@{
/**
* @param x A %reverse_iterator.
* @param y A %reverse_iterator.
* @return A simple bool.
*
* Reverse iterators forward many operations to their underlying base()
* iterators. Others are implemented in terms of one another.
*
*/
template<typename _Iterator>
inline bool
operator==(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return __x.base() == __y.base(); }
template<typename _Iterator>
inline bool
operator<(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return __y.base() < __x.base(); }
template<typename _Iterator>
inline bool
operator!=(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return !(__x == __y); }
template<typename _Iterator>
inline bool
operator>(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return __y < __x; }
template<typename _Iterator>
inline bool
operator<=(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return !(__y < __x); }
template<typename _Iterator>
inline bool
operator>=(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return !(__x < __y); }
template<typename _Iterator>
inline typename reverse_iterator<_Iterator>::difference_type
operator-(const reverse_iterator<_Iterator>& __x,
const reverse_iterator<_Iterator>& __y)
{ return __y.base() - __x.base(); }
template<typename _Iterator>
inline reverse_iterator<_Iterator>
operator+(typename reverse_iterator<_Iterator>::difference_type __n,
const reverse_iterator<_Iterator>& __x)
{ return reverse_iterator<_Iterator>(__x.base() - __n); }
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 280. Comparison of reverse_iterator to const reverse_iterator.
template<typename _IteratorL, typename _IteratorR>
inline bool
operator==(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return __x.base() == __y.base(); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator<(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return __y.base() < __x.base(); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator!=(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return !(__x == __y); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator>(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return __y < __x; }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator<=(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return !(__y < __x); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator>=(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return !(__x < __y); }
template<typename _IteratorL, typename _IteratorR>
inline typename reverse_iterator<_IteratorL>::difference_type
operator-(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
{ return __y.base() - __x.base(); }
//@}
// 24.4.2.2.1 back_insert_iterator
/**
* @brief Turns assignment into insertion.
*
* These are output iterators, constructed from a container-of-T.
* Assigning a T to the iterator appends it to the container using
* push_back.
*
* Tip: Using the back_inserter function to create these iterators can
* save typing.
*/
template<typename _Container>
class back_insert_iterator
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
_Container* container;
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
/// The only way to create this %iterator is with a container.
explicit
back_insert_iterator(_Container& __x) : container(&__x) { }
/**
* @param value An instance of whatever type
* container_type::const_reference is; presumably a
* reference-to-const T for container<T>.
* @return This %iterator, for chained operations.
*
* This kind of %iterator doesn't really have a "position" in the
* container (you can think of the position as being permanently at
* the end, if you like). Assigning a value to the %iterator will
* always append the value to the end of the container.
*/
back_insert_iterator&
operator=(typename _Container::const_reference __value)
{
container->push_back(__value);
return *this;
}
/// Simply returns *this.
back_insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not "move".)
back_insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not "move".)
back_insert_iterator
operator++(int)
{ return *this; }
};
/**
* @param x A container of arbitrary type.
* @return An instance of back_insert_iterator working on @p x.
*
* This wrapper function helps in creating back_insert_iterator instances.
* Typing the name of the %iterator requires knowing the precise full
* type of the container, which can be tedious and impedes generic
* programming. Using this function lets you take advantage of automatic
* template parameter deduction, making the compiler match the correct
* types for you.
*/
template<typename _Container>
inline back_insert_iterator<_Container>
back_inserter(_Container& __x)
{ return back_insert_iterator<_Container>(__x); }
/**
* @brief Turns assignment into insertion.
*
* These are output iterators, constructed from a container-of-T.
* Assigning a T to the iterator prepends it to the container using
* push_front.
*
* Tip: Using the front_inserter function to create these iterators can
* save typing.
*/
template<typename _Container>
class front_insert_iterator
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
_Container* container;
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
/// The only way to create this %iterator is with a container.
explicit front_insert_iterator(_Container& __x) : container(&__x) { }
/**
* @param value An instance of whatever type
* container_type::const_reference is; presumably a
* reference-to-const T for container<T>.
* @return This %iterator, for chained operations.
*
* This kind of %iterator doesn't really have a "position" in the
* container (you can think of the position as being permanently at
* the front, if you like). Assigning a value to the %iterator will
* always prepend the value to the front of the container.
*/
front_insert_iterator&
operator=(typename _Container::const_reference __value)
{
container->push_front(__value);
return *this;
}
/// Simply returns *this.
front_insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not "move".)
front_insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not "move".)
front_insert_iterator
operator++(int)
{ return *this; }
};
/**
* @param x A container of arbitrary type.
* @return An instance of front_insert_iterator working on @p x.
*
* This wrapper function helps in creating front_insert_iterator instances.
* Typing the name of the %iterator requires knowing the precise full
* type of the container, which can be tedious and impedes generic
* programming. Using this function lets you take advantage of automatic
* template parameter deduction, making the compiler match the correct
* types for you.
*/
template<typename _Container>
inline front_insert_iterator<_Container>
front_inserter(_Container& __x)
{ return front_insert_iterator<_Container>(__x); }
/**
* @brief Turns assignment into insertion.
*
* These are output iterators, constructed from a container-of-T.
* Assigning a T to the iterator inserts it in the container at the
* %iterator's position, rather than overwriting the value at that
* position.
*
* (Sequences will actually insert a @e copy of the value before the
* %iterator's position.)
*
* Tip: Using the inserter function to create these iterators can
* save typing.
*/
template<typename _Container>
class insert_iterator
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
_Container* container;
typename _Container::iterator iter;
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
/**
* The only way to create this %iterator is with a container and an
* initial position (a normal %iterator into the container).
*/
insert_iterator(_Container& __x, typename _Container::iterator __i)
: container(&__x), iter(__i) {}
/**
* @param value An instance of whatever type
* container_type::const_reference is; presumably a
* reference-to-const T for container<T>.
* @return This %iterator, for chained operations.
*
* This kind of %iterator maintains its own position in the
* container. Assigning a value to the %iterator will insert the
* value into the container at the place before the %iterator.
*
* The position is maintained such that subsequent assignments will
* insert values immediately after one another. For example,
* @code
* // vector v contains A and Z
*
* insert_iterator i (v, ++v.begin());
* i = 1;
* i = 2;
* i = 3;
*
* // vector v contains A, 1, 2, 3, and Z
* @endcode
*/
insert_iterator&
operator=(const typename _Container::const_reference __value)
{
iter = container->insert(iter, __value);
++iter;
return *this;
}
/// Simply returns *this.
insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not "move".)
insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not "move".)
insert_iterator&
operator++(int)
{ return *this; }
};
/**
* @param x A container of arbitrary type.
* @return An instance of insert_iterator working on @p x.
*
* This wrapper function helps in creating insert_iterator instances.
* Typing the name of the %iterator requires knowing the precise full
* type of the container, which can be tedious and impedes generic
* programming. Using this function lets you take advantage of automatic
* template parameter deduction, making the compiler match the correct
* types for you.
*/
template<typename _Container, typename _Iterator>
inline insert_iterator<_Container>
inserter(_Container& __x, _Iterator __i)
{
return insert_iterator<_Container>(__x,
typename _Container::iterator(__i));
}
_GLIBCXX_END_NAMESPACE
_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
// This iterator adapter is 'normal' in the sense that it does not
// change the semantics of any of the operators of its iterator
// parameter. Its primary purpose is to convert an iterator that is
// not a class, e.g. a pointer, into an iterator that is a class.
// The _Container parameter exists solely so that different containers
// using this template can instantiate different types, even if the
// _Iterator parameter is the same.
using std::iterator_traits;
using std::iterator;
template<typename _Iterator, typename _Container>
class __normal_iterator
{
protected:
_Iterator _M_current;
public:
typedef typename iterator_traits<_Iterator>::iterator_category
iterator_category;
typedef typename iterator_traits<_Iterator>::value_type value_type;
typedef typename iterator_traits<_Iterator>::difference_type
difference_type;
typedef typename iterator_traits<_Iterator>::reference reference;
typedef typename iterator_traits<_Iterator>::pointer pointer;
__normal_iterator() : _M_current(_Iterator()) { }
explicit
__normal_iterator(const _Iterator& __i) : _M_current(__i) { }
// Allow iterator to const_iterator conversion
template<typename _Iter>
__normal_iterator(const __normal_iterator<_Iter,
typename __enable_if<
(std::__are_same<_Iter, typename _Container::pointer>::__value),
_Container>::__type>& __i)
: _M_current(__i.base()) { }
// Forward iterator requirements
reference
operator*() const
{ return *_M_current; }
pointer
operator->() const
{ return _M_current; }
__normal_iterator&
operator++()
{
++_M_current;
return *this;
}
__normal_iterator
operator++(int)
{ return __normal_iterator(_M_current++); }
// Bidirectional iterator requirements
__normal_iterator&
operator--()
{
--_M_current;
return *this;
}
__normal_iterator
operator--(int)
{ return __normal_iterator(_M_current--); }
// Random access iterator requirements
reference
operator[](const difference_type& __n) const
{ return _M_current[__n]; }
__normal_iterator&
operator+=(const difference_type& __n)
{ _M_current += __n; return *this; }
__normal_iterator
operator+(const difference_type& __n) const
{ return __normal_iterator(_M_current + __n); }
__normal_iterator&
operator-=(const difference_type& __n)
{ _M_current -= __n; return *this; }
__normal_iterator
operator-(const difference_type& __n) const
{ return __normal_iterator(_M_current - __n); }
const _Iterator&
base() const
{ return _M_current; }
};
// Note: In what follows, the left- and right-hand-side iterators are
// allowed to vary in types (conceptually in cv-qualification) so that
// comparaison between cv-qualified and non-cv-qualified iterators be
// valid. However, the greedy and unfriendly operators in std::rel_ops
// will make overload resolution ambiguous (when in scope) if we don't
// provide overloads whose operands are of the same type. Can someone
// remind me what generic programming is about? -- Gaby
// Forward iterator requirements
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline bool
operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() == __rhs.base(); }
template<typename _Iterator, typename _Container>
inline bool
operator==(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() == __rhs.base(); }
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline bool
operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() != __rhs.base(); }
template<typename _Iterator, typename _Container>
inline bool
operator!=(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() != __rhs.base(); }
// Random access iterator requirements
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline bool
operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() < __rhs.base(); }
template<typename _Iterator, typename _Container>
inline bool
operator<(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() < __rhs.base(); }
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline bool
operator>(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() > __rhs.base(); }
template<typename _Iterator, typename _Container>
inline bool
operator>(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() > __rhs.base(); }
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline bool
operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() <= __rhs.base(); }
template<typename _Iterator, typename _Container>
inline bool
operator<=(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() <= __rhs.base(); }
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline bool
operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() >= __rhs.base(); }
template<typename _Iterator, typename _Container>
inline bool
operator>=(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() >= __rhs.base(); }
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// According to the resolution of DR179 not only the various comparison
// operators but also operator- must accept mixed iterator/const_iterator
// parameters.
template<typename _IteratorL, typename _IteratorR, typename _Container>
inline typename __normal_iterator<_IteratorL, _Container>::difference_type
operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() - __rhs.base(); }
template<typename _Iterator, typename _Container>
inline typename __normal_iterator<_Iterator, _Container>::difference_type
operator-(const __normal_iterator<_Iterator, _Container>& __lhs,
const __normal_iterator<_Iterator, _Container>& __rhs)
{ return __lhs.base() - __rhs.base(); }
template<typename _Iterator, typename _Container>
inline __normal_iterator<_Iterator, _Container>
operator+(typename __normal_iterator<_Iterator, _Container>::difference_type
__n, const __normal_iterator<_Iterator, _Container>& __i)
{ return __normal_iterator<_Iterator, _Container>(__i.base() + __n); }
_GLIBCXX_END_NAMESPACE
#endif
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