stl_iterator.h
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// Iterators -*- C++ -*-
// Copyright (C) 2001-2013 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 3, 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.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* 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 bits/stl_iterator.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{iterator}
*
* This file implements reverse_iterator, back_insert_iterator,
* front_insert_iterator, insert_iterator, __normal_iterator, and their
* supporting functions and overloaded operators.
*/
#ifndef _STL_ITERATOR_H
#define _STL_ITERATOR_H 1
#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>
#include <bits/move.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup iterators
* @{
*/
// 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
*
* <em>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.</em> [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;
typedef iterator_traits<_Iterator> __traits_type;
public:
typedef _Iterator iterator_type;
typedef typename __traits_type::difference_type difference_type;
typedef typename __traits_type::pointer pointer;
typedef typename __traits_type::reference reference;
/**
* The default constructor value-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 if the
* underlying %iterator can be converted to the type of @c current.
*/
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 A reference to the value at @c --current
*
* This requires that @c --current is dereferenceable.
*
* @warning This implementation requires that for an iterator of the
* underlying iterator type, @c x, a reference obtained by
* @c *x remains valid after @c x has been modified or
* destroyed. This is a bug: http://gcc.gnu.org/PR51823
*/
reference
operator*() const
{
_Iterator __tmp = current;
return *--__tmp;
}
/**
* @return A pointer to the value at @c --current
*
* This requires that @c --current is dereferenceable.
*/
pointer
operator->() const
{ return &(operator*()); }
/**
* @return @c *this
*
* Decrements the underlying iterator.
*/
reverse_iterator&
operator++()
{
--current;
return *this;
}
/**
* @return The original value of @c *this
*
* Decrements the underlying iterator.
*/
reverse_iterator
operator++(int)
{
reverse_iterator __tmp = *this;
--current;
return __tmp;
}
/**
* @return @c *this
*
* Increments the underlying iterator.
*/
reverse_iterator&
operator--()
{
++current;
return *this;
}
/**
* @return A reverse_iterator with the previous value of @c *this
*
* Increments the underlying iterator.
*/
reverse_iterator
operator--(int)
{
reverse_iterator __tmp = *this;
++current;
return __tmp;
}
/**
* @return A reverse_iterator that refers to @c current - @a __n
*
* The underlying iterator must be a Random Access Iterator.
*/
reverse_iterator
operator+(difference_type __n) const
{ return reverse_iterator(current - __n); }
/**
* @return *this
*
* Moves the underlying iterator backwards @a __n steps.
* The underlying iterator must be a Random Access Iterator.
*/
reverse_iterator&
operator+=(difference_type __n)
{
current -= __n;
return *this;
}
/**
* @return A reverse_iterator that refers to @c current - @a __n
*
* The underlying iterator must be a Random Access Iterator.
*/
reverse_iterator
operator-(difference_type __n) const
{ return reverse_iterator(current + __n); }
/**
* @return *this
*
* Moves the underlying iterator forwards @a __n steps.
* The underlying iterator must be a Random Access Iterator.
*/
reverse_iterator&
operator-=(difference_type __n)
{
current += __n;
return *this;
}
/**
* @return The value at @c current - @a __n - 1
*
* The underlying iterator must be a Random Access Iterator.
*/
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>
#if __cplusplus >= 201103L
// DR 685.
inline auto
operator-(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
-> decltype(__y.base() - __x.base())
#else
inline typename reverse_iterator<_IteratorL>::difference_type
operator-(const reverse_iterator<_IteratorL>& __x,
const reverse_iterator<_IteratorR>& __y)
#endif
{ 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 @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.
*/
#if __cplusplus < 201103L
back_insert_iterator&
operator=(typename _Container::const_reference __value)
{
container->push_back(__value);
return *this;
}
#else
back_insert_iterator&
operator=(const typename _Container::value_type& __value)
{
container->push_back(__value);
return *this;
}
back_insert_iterator&
operator=(typename _Container::value_type&& __value)
{
container->push_back(std::move(__value));
return *this;
}
#endif
/// Simply returns *this.
back_insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
back_insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a 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 @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.
*/
#if __cplusplus < 201103L
front_insert_iterator&
operator=(typename _Container::const_reference __value)
{
container->push_front(__value);
return *this;
}
#else
front_insert_iterator&
operator=(const typename _Container::value_type& __value)
{
container->push_front(__value);
return *this;
}
front_insert_iterator&
operator=(typename _Container::value_type&& __value)
{
container->push_front(std::move(__value));
return *this;
}
#endif
/// Simply returns *this.
front_insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
front_insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a 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
*/
#if __cplusplus < 201103L
insert_iterator&
operator=(typename _Container::const_reference __value)
{
iter = container->insert(iter, __value);
++iter;
return *this;
}
#else
insert_iterator&
operator=(const typename _Container::value_type& __value)
{
iter = container->insert(iter, __value);
++iter;
return *this;
}
insert_iterator&
operator=(typename _Container::value_type&& __value)
{
iter = container->insert(iter, std::move(__value));
++iter;
return *this;
}
#endif
/// Simply returns *this.
insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a 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));
}
// @} group iterators
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// This iterator adapter is @a 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;
typedef iterator_traits<_Iterator> __traits_type;
public:
typedef _Iterator iterator_type;
typedef typename __traits_type::iterator_category iterator_category;
typedef typename __traits_type::value_type value_type;
typedef typename __traits_type::difference_type difference_type;
typedef typename __traits_type::reference reference;
typedef typename __traits_type::pointer pointer;
_GLIBCXX_CONSTEXPR __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
// comparison 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>
#if __cplusplus >= 201103L
// DR 685.
inline auto
operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
-> decltype(__lhs.base() - __rhs.base())
#else
inline typename __normal_iterator<_IteratorL, _Container>::difference_type
operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
const __normal_iterator<_IteratorR, _Container>& __rhs)
#endif
{ 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_VERSION
} // namespace
#if __cplusplus >= 201103L
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup iterators
* @{
*/
// 24.4.3 Move iterators
/**
* Class template move_iterator is an iterator adapter with the same
* behavior as the underlying iterator except that its dereference
* operator implicitly converts the value returned by the underlying
* iterator's dereference operator to an rvalue reference. Some
* generic algorithms can be called with move iterators to replace
* copying with moving.
*/
template<typename _Iterator>
class move_iterator
{
protected:
_Iterator _M_current;
typedef iterator_traits<_Iterator> __traits_type;
public:
typedef _Iterator iterator_type;
typedef typename __traits_type::iterator_category iterator_category;
typedef typename __traits_type::value_type value_type;
typedef typename __traits_type::difference_type difference_type;
// NB: DR 680.
typedef _Iterator pointer;
typedef value_type&& reference;
move_iterator()
: _M_current() { }
explicit
move_iterator(iterator_type __i)
: _M_current(__i) { }
template<typename _Iter>
move_iterator(const move_iterator<_Iter>& __i)
: _M_current(__i.base()) { }
iterator_type
base() const
{ return _M_current; }
reference
operator*() const
{ return std::move(*_M_current); }
pointer
operator->() const
{ return _M_current; }
move_iterator&
operator++()
{
++_M_current;
return *this;
}
move_iterator
operator++(int)
{
move_iterator __tmp = *this;
++_M_current;
return __tmp;
}
move_iterator&
operator--()
{
--_M_current;
return *this;
}
move_iterator
operator--(int)
{
move_iterator __tmp = *this;
--_M_current;
return __tmp;
}
move_iterator
operator+(difference_type __n) const
{ return move_iterator(_M_current + __n); }
move_iterator&
operator+=(difference_type __n)
{
_M_current += __n;
return *this;
}
move_iterator
operator-(difference_type __n) const
{ return move_iterator(_M_current - __n); }
move_iterator&
operator-=(difference_type __n)
{
_M_current -= __n;
return *this;
}
reference
operator[](difference_type __n) const
{ return std::move(_M_current[__n]); }
};
// Note: See __normal_iterator operators note from Gaby to understand
// why there are always 2 versions for most of the move_iterator
// operators.
template<typename _IteratorL, typename _IteratorR>
inline bool
operator==(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
{ return __x.base() == __y.base(); }
template<typename _Iterator>
inline bool
operator==(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
{ return __x.base() == __y.base(); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator!=(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
{ return !(__x == __y); }
template<typename _Iterator>
inline bool
operator!=(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
{ return !(__x == __y); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator<(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
{ return __x.base() < __y.base(); }
template<typename _Iterator>
inline bool
operator<(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
{ return __x.base() < __y.base(); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator<=(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
{ return !(__y < __x); }
template<typename _Iterator>
inline bool
operator<=(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
{ return !(__y < __x); }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator>(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
{ return __y < __x; }
template<typename _Iterator>
inline bool
operator>(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
{ return __y < __x; }
template<typename _IteratorL, typename _IteratorR>
inline bool
operator>=(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
{ return !(__x < __y); }
template<typename _Iterator>
inline bool
operator>=(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
{ return !(__x < __y); }
// DR 685.
template<typename _IteratorL, typename _IteratorR>
inline auto
operator-(const move_iterator<_IteratorL>& __x,
const move_iterator<_IteratorR>& __y)
-> decltype(__x.base() - __y.base())
{ return __x.base() - __y.base(); }
template<typename _Iterator>
inline auto
operator-(const move_iterator<_Iterator>& __x,
const move_iterator<_Iterator>& __y)
-> decltype(__x.base() - __y.base())
{ return __x.base() - __y.base(); }
template<typename _Iterator>
inline move_iterator<_Iterator>
operator+(typename move_iterator<_Iterator>::difference_type __n,
const move_iterator<_Iterator>& __x)
{ return __x + __n; }
template<typename _Iterator>
inline move_iterator<_Iterator>
make_move_iterator(_Iterator __i)
{ return move_iterator<_Iterator>(__i); }
template<typename _Iterator, typename _ReturnType
= typename conditional<__move_if_noexcept_cond
<typename iterator_traits<_Iterator>::value_type>::value,
_Iterator, move_iterator<_Iterator>>::type>
inline _ReturnType
__make_move_if_noexcept_iterator(_Iterator __i)
{ return _ReturnType(__i); }
// @} group iterators
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#define _GLIBCXX_MAKE_MOVE_ITERATOR(_Iter) std::make_move_iterator(_Iter)
#define _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(_Iter) \
std::__make_move_if_noexcept_iterator(_Iter)
#else
#define _GLIBCXX_MAKE_MOVE_ITERATOR(_Iter) (_Iter)
#define _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(_Iter) (_Iter)
#endif // C++11
#endif