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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef ITERATORS_H
#define ITERATORS_H
#include <iterator>
template <class It>
class output_iterator
{
It it_;
template <class U> friend class output_iterator;
public:
typedef std::output_iterator_tag iterator_category;
typedef void value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
It base() const {return it_;}
output_iterator () {}
explicit output_iterator(It it) : it_(it) {}
template <class U>
output_iterator(const output_iterator<U>& u) :it_(u.it_) {}
reference operator*() const {return *it_;}
output_iterator& operator++() {++it_; return *this;}
output_iterator operator++(int)
{output_iterator tmp(*this); ++(*this); return tmp;}
};
template <class It>
class input_iterator
{
It it_;
template <class U> friend class input_iterator;
public:
typedef std::input_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
It base() const {return it_;}
input_iterator() : it_() {}
explicit input_iterator(It it) : it_(it) {}
template <class U>
input_iterator(const input_iterator<U>& u) :it_(u.it_) {}
reference operator*() const {return *it_;}
pointer operator->() const {return it_;}
input_iterator& operator++() {++it_; return *this;}
input_iterator operator++(int)
{input_iterator tmp(*this); ++(*this); return tmp;}
friend bool operator==(const input_iterator& x, const input_iterator& y)
{return x.it_ == y.it_;}
friend bool operator!=(const input_iterator& x, const input_iterator& y)
{return !(x == y);}
};
template <class T, class U>
inline
bool
operator==(const input_iterator<T>& x, const input_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
inline
bool
operator!=(const input_iterator<T>& x, const input_iterator<U>& y)
{
return !(x == y);
}
template <class It>
class forward_iterator
{
It it_;
template <class U> friend class forward_iterator;
public:
typedef std::forward_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
It base() const {return it_;}
forward_iterator() : it_() {}
explicit forward_iterator(It it) : it_(it) {}
template <class U>
forward_iterator(const forward_iterator<U>& u) :it_(u.it_) {}
reference operator*() const {return *it_;}
pointer operator->() const {return it_;}
forward_iterator& operator++() {++it_; return *this;}
forward_iterator operator++(int)
{forward_iterator tmp(*this); ++(*this); return tmp;}
friend bool operator==(const forward_iterator& x, const forward_iterator& y)
{return x.it_ == y.it_;}
friend bool operator!=(const forward_iterator& x, const forward_iterator& y)
{return !(x == y);}
};
template <class T, class U>
inline
bool
operator==(const forward_iterator<T>& x, const forward_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
inline
bool
operator!=(const forward_iterator<T>& x, const forward_iterator<U>& y)
{
return !(x == y);
}
template <class It>
class bidirectional_iterator
{
It it_;
template <class U> friend class bidirectional_iterator;
public:
typedef std::bidirectional_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
It base() const {return it_;}
bidirectional_iterator() : it_() {}
explicit bidirectional_iterator(It it) : it_(it) {}
template <class U>
bidirectional_iterator(const bidirectional_iterator<U>& u) :it_(u.it_) {}
reference operator*() const {return *it_;}
pointer operator->() const {return it_;}
bidirectional_iterator& operator++() {++it_; return *this;}
bidirectional_iterator operator++(int)
{bidirectional_iterator tmp(*this); ++(*this); return tmp;}
bidirectional_iterator& operator--() {--it_; return *this;}
bidirectional_iterator operator--(int)
{bidirectional_iterator tmp(*this); --(*this); return tmp;}
};
template <class T, class U>
inline
bool
operator==(const bidirectional_iterator<T>& x, const bidirectional_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
inline
bool
operator!=(const bidirectional_iterator<T>& x, const bidirectional_iterator<U>& y)
{
return !(x == y);
}
template <class It>
class random_access_iterator
{
It it_;
template <class U> friend class random_access_iterator;
public:
typedef std::random_access_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
It base() const {return it_;}
random_access_iterator() : it_() {}
explicit random_access_iterator(It it) : it_(it) {}
template <class U>
random_access_iterator(const random_access_iterator<U>& u) :it_(u.it_) {}
reference operator*() const {return *it_;}
pointer operator->() const {return it_;}
random_access_iterator& operator++() {++it_; return *this;}
random_access_iterator operator++(int)
{random_access_iterator tmp(*this); ++(*this); return tmp;}
random_access_iterator& operator--() {--it_; return *this;}
random_access_iterator operator--(int)
{random_access_iterator tmp(*this); --(*this); return tmp;}
random_access_iterator& operator+=(difference_type n) {it_ += n; return *this;}
random_access_iterator operator+(difference_type n) const
{random_access_iterator tmp(*this); tmp += n; return tmp;}
friend random_access_iterator operator+(difference_type n, random_access_iterator x)
{x += n; return x;}
random_access_iterator& operator-=(difference_type n) {return *this += -n;}
random_access_iterator operator-(difference_type n) const
{random_access_iterator tmp(*this); tmp -= n; return tmp;}
reference operator[](difference_type n) const {return it_[n];}
};
template <class T, class U>
inline
bool
operator==(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
inline
bool
operator!=(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return !(x == y);
}
template <class T, class U>
inline
bool
operator<(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return x.base() < y.base();
}
template <class T, class U>
inline
bool
operator<=(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return !(y < x);
}
template <class T, class U>
inline
bool
operator>(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return y < x;
}
template <class T, class U>
inline
bool
operator>=(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return !(x < y);
}
template <class T, class U>
inline
typename std::iterator_traits<T>::difference_type
operator-(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return x.base() - y.base();
}
template <class Iter>
inline Iter base(output_iterator<Iter> i) { return i.base(); }
template <class Iter>
inline Iter base(input_iterator<Iter> i) { return i.base(); }
template <class Iter>
inline Iter base(forward_iterator<Iter> i) { return i.base(); }
template <class Iter>
inline Iter base(bidirectional_iterator<Iter> i) { return i.base(); }
template <class Iter>
inline Iter base(random_access_iterator<Iter> i) { return i.base(); }
template <class Iter> // everything else
inline Iter base(Iter i) { return i; }
#endif // ITERATORS_H
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