Add libc++ and libc++abi to third-party.

third_party/libcxx/include/iterator

Index: third_party/libcxx/include/iterator
===================================================================
--- third_party/libcxx/include/iterator	(revision 0)
+++ third_party/libcxx/include/iterator	(revision 0)
@@ -0,0 +1,1568 @@
+// -*- C++ -*-
+//===-------------------------- iterator ----------------------------------===//
+//
+//                     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 _LIBCPP_ITERATOR
+#define _LIBCPP_ITERATOR
+
+/*
+    iterator synopsis
+
+namespace std
+{
+
+template<class Iterator>
+struct iterator_traits
+{
+    typedef typename Iterator::difference_type difference_type;
+    typedef typename Iterator::value_type value_type;
+    typedef typename Iterator::pointer pointer;
+    typedef typename Iterator::reference reference;
+    typedef typename Iterator::iterator_category iterator_category;
+};
+
+template<class T>
+struct iterator_traits<T*>
+{
+    typedef ptrdiff_t difference_type;
+    typedef T value_type;
+    typedef T* pointer;
+    typedef T& reference;
+    typedef random_access_iterator_tag iterator_category;
+};
+
+template<class T>
+struct iterator_traits<const T*>
+{
+    typedef ptrdiff_t difference_type;
+    typedef T value_type;
+    typedef const T* pointer;
+    typedef const T& reference;
+    typedef random_access_iterator_tag iterator_category;
+};
+
+template<class Category, class T, class Distance = ptrdiff_t,
+         class Pointer = T*, class Reference = T&>
+struct iterator
+{
+    typedef T         value_type;
+    typedef Distance  difference_type;
+    typedef Pointer   pointer;
+    typedef Reference reference;
+    typedef Category  iterator_category;
+};
+
+struct input_iterator_tag  {};
+struct output_iterator_tag {};
+struct forward_iterator_tag       : public input_iterator_tag         {};
+struct bidirectional_iterator_tag : public forward_iterator_tag       {};
+struct random_access_iterator_tag : public bidirectional_iterator_tag {};
+
+// extension: second argument not conforming to C++03
+template <class InputIterator>
+void advance(InputIterator& i,
+             typename iterator_traits<InputIterator>::difference_type n);
+
+template <class InputIterator>
+typename iterator_traits<InputIterator>::difference_type
+distance(InputIterator first, InputIterator last);
+
+template <class 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;
+
+    reverse_iterator();
+    explicit reverse_iterator(Iterator x);
+    template <class U> reverse_iterator(const reverse_iterator<U>& u);
+    Iterator base() const;
+    reference operator*() const;
+    pointer   operator->() const;
+    reverse_iterator& operator++();
+    reverse_iterator  operator++(int);
+    reverse_iterator& operator--();
+    reverse_iterator  operator--(int);
+    reverse_iterator  operator+ (difference_type n) const;
+    reverse_iterator& operator+=(difference_type n);
+    reverse_iterator  operator- (difference_type n) const;
+    reverse_iterator& operator-=(difference_type n);
+    reference         operator[](difference_type n) const;
+};
+
+template <class Iterator1, class Iterator2>
+bool
+operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+typename reverse_iterator<Iterator1>::difference_type
+operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator>
+reverse_iterator<Iterator>
+operator+(typename reverse_iterator<Iterator>::difference_type n, const reverse_iterator<Iterator>& x);
+
+template <class Container>
+class back_insert_iterator
+{
+protected:
+    Container* container;
+public:
+    typedef Container                   container_type;
+    typedef void                        value_type;
+    typedef void                        difference_type;
+    typedef back_insert_iterator<Cont>& reference;
+    typedef void                        pointer;
+
+    explicit back_insert_iterator(Container& x);
+    back_insert_iterator& operator=(const typename Container::value_type& value);
+    back_insert_iterator& operator*();
+    back_insert_iterator& operator++();
+    back_insert_iterator  operator++(int);
+};
+
+template <class Container> back_insert_iterator<Container> back_inserter(Container& x);
+
+template <class Container>
+class front_insert_iterator
+{
+protected:
+    Container* container;
+public:
+    typedef Container                    container_type;
+    typedef void                         value_type;
+    typedef void                         difference_type;
+    typedef front_insert_iterator<Cont>& reference;
+    typedef void                         pointer;
+
+    explicit front_insert_iterator(Container& x);
+    front_insert_iterator& operator=(const typename Container::value_type& value);
+    front_insert_iterator& operator*();
+    front_insert_iterator& operator++();
+    front_insert_iterator  operator++(int);
+};
+
+template <class Container> front_insert_iterator<Container> front_inserter(Container& x);
+
+template <class Container>
+class insert_iterator
+{
+protected:
+    Container* container;
+    typename Container::iterator iter;
+public:
+    typedef Container              container_type;
+    typedef void                   value_type;
+    typedef void                   difference_type;
+    typedef insert_iterator<Cont>& reference;
+    typedef void                   pointer;
+
+    insert_iterator(Container& x, typename Container::iterator i);
+    insert_iterator& operator=(const typename Container::value_type& value);
+    insert_iterator& operator*();
+    insert_iterator& operator++();
+    insert_iterator& operator++(int);
+};
+
+template <class Container, class Iterator>
+insert_iterator<Container> inserter(Container& x, Iterator i);
+
+template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
+class istream_iterator
+    : public iterator<input_iterator_tag, T, Distance, const T*, const T&>
+{
+public:
+    typedef charT char_type;
+    typedef traits traits_type;
+    typedef basic_istream<charT,traits> istream_type;
+
+    istream_iterator();
+    istream_iterator(istream_type& s);
+    istream_iterator(const istream_iterator& x);
+    ~istream_iterator();
+
+    const T& operator*() const;
+    const T* operator->() const;
+    istream_iterator& operator++();
+    istream_iterator  operator++(int);
+};
+
+template <class T, class charT, class traits, class Distance>
+bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
+                const istream_iterator<T,charT,traits,Distance>& y);
+template <class T, class charT, class traits, class Distance>
+bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
+                const istream_iterator<T,charT,traits,Distance>& y);
+
+template <class T, class charT = char, class traits = char_traits<charT> >
+class ostream_iterator
+    : public iterator<output_iterator_tag, void, void, void ,void>
+{
+public:
+    typedef charT char_type;
+    typedef traits traits_type;
+    typedef basic_ostream<charT,traits> ostream_type;
+
+    ostream_iterator(ostream_type& s);
+    ostream_iterator(ostream_type& s, const charT* delimiter);
+    ostream_iterator(const ostream_iterator& x);
+    ~ostream_iterator();
+    ostream_iterator& operator=(const T& value);
+
+    ostream_iterator& operator*();
+    ostream_iterator& operator++();
+    ostream_iterator& operator++(int);
+};
+
+template<class charT, class traits = char_traits<charT> >
+class istreambuf_iterator
+    : public iterator<input_iterator_tag, charT,
+                      typename traits::off_type, unspecified,
+                      charT>
+{
+public:
+    typedef charT                         char_type;
+    typedef traits                        traits_type;
+    typedef typename traits::int_type     int_type;
+    typedef basic_streambuf<charT,traits> streambuf_type;
+    typedef basic_istream<charT,traits>   istream_type;
+
+    istreambuf_iterator() noexcept;
+    istreambuf_iterator(istream_type& s) noexcept;
+    istreambuf_iterator(streambuf_type* s) noexcept;
+    istreambuf_iterator(a-private-type) noexcept;
+
+    charT                operator*() const;
+    pointer operator->() const;
+    istreambuf_iterator& operator++();
+    a-private-type       operator++(int);
+
+    bool equal(const istreambuf_iterator& b) const;
+};
+
+template <class charT, class traits>
+bool operator==(const istreambuf_iterator<charT,traits>& a,
+                const istreambuf_iterator<charT,traits>& b);
+template <class charT, class traits>
+bool operator!=(const istreambuf_iterator<charT,traits>& a,
+                const istreambuf_iterator<charT,traits>& b);
+
+template <class charT, class traits = char_traits<charT> >
+class ostreambuf_iterator
+    : public iterator<output_iterator_tag, void, void, void, void>
+{
+public:
+    typedef charT                         char_type;
+    typedef traits                        traits_type;
+    typedef basic_streambuf<charT,traits> streambuf_type;
+    typedef basic_ostream<charT,traits>   ostream_type;
+
+    ostreambuf_iterator(ostream_type& s) noexcept;
+    ostreambuf_iterator(streambuf_type* s) noexcept;
+    ostreambuf_iterator& operator=(charT c);
+    ostreambuf_iterator& operator*();
+    ostreambuf_iterator& operator++();
+    ostreambuf_iterator& operator++(int);
+    bool failed() const noexcept;
+};
+
+template <class C> auto begin(C& c) -> decltype(c.begin());
+template <class C> auto begin(const C& c) -> decltype(c.begin());
+template <class C> auto end(C& c) -> decltype(c.end());
+template <class C> auto end(const C& c) -> decltype(c.end());
+template <class T, size_t N> T* begin(T (&array)[N]);
+template <class T, size_t N> T* end(T (&array)[N]);
+
+template <class C> auto cbegin(const C& c) -> decltype(std::begin(c));        // C++14
+template <class C> auto cend(const C& c) -> decltype(std::end(c));            // C++14
+template <class C> auto rbegin(C& c) -> decltype(c.rbegin());                 // C++14
+template <class C> auto rbegin(const C& c) -> decltype(c.rbegin());           // C++14
+template <class C> auto rend(C& c) -> decltype(c.rend());                     // C++14
+template <class C> auto rend(const C& c) -> decltype(c.rend());               // C++14
+template <class E> reverse_iterator<const E*> rbegin(initializer_list<E> il); // C++14
+template <class E> reverse_iterator<const E*> rend(initializer_list<E> il);   // C++14
+template <class T, size_t N> reverse_iterator<T*> rbegin(T (&array)[N]);      // C++14
+template <class T, size_t N> reverse_iterator<T*> rend(T (&array)[N]);        // C++14
+template <class C> auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
+template <class C> auto crend(const C& c) -> decltype(std::rend(c));          // C++14
+
+}  // std
+
+*/
+
+#include <__config>
+#include <type_traits>
+#include <cstddef>
+#include <iosfwd>
+#include <initializer_list>
+#ifdef __APPLE__
+#include <Availability.h>
+#endif
+
+#ifdef _LIBCPP_DEBUG
+#   include <__debug>
+#else
+#   define _LIBCPP_ASSERT(x, m) ((void)0)
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+struct _LIBCPP_TYPE_VIS_ONLY input_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY output_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY forward_iterator_tag       : public input_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY bidirectional_iterator_tag : public forward_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY random_access_iterator_tag : public bidirectional_iterator_tag {};
+
+template <class _Tp>
+struct __has_iterator_category
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::iterator_category* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Iter, bool> struct ____iterator_traits {};
+
+template <class _Iter>
+struct ____iterator_traits<_Iter, true>
+{
+    typedef typename _Iter::difference_type   difference_type;
+    typedef typename _Iter::value_type        value_type;
+    typedef typename _Iter::pointer           pointer;
+    typedef typename _Iter::reference         reference;
+    typedef typename _Iter::iterator_category iterator_category;
+};
+
+template <class _Iter, bool> struct __iterator_traits {};
+
+template <class _Iter>
+struct __iterator_traits<_Iter, true>
+    :  ____iterator_traits
+      <
+        _Iter,
+        is_convertible<typename _Iter::iterator_category, input_iterator_tag>::value ||
+        is_convertible<typename _Iter::iterator_category, output_iterator_tag>::value
+      >
+{};
+
+// iterator_traits<Iterator> will only have the nested types if Iterator::iterator_category
+//    exists.  Else iterator_traits<Iterator> will be an empty class.  This is a
+//    conforming extension which allows some programs to compile and behave as
+//    the client expects instead of failing at compile time.
+
+template <class _Iter>
+struct _LIBCPP_TYPE_VIS_ONLY iterator_traits
+    : __iterator_traits<_Iter, __has_iterator_category<_Iter>::value> {};
+
+template<class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY iterator_traits<_Tp*>
+{
+    typedef ptrdiff_t difference_type;
+    typedef typename remove_const<_Tp>::type value_type;
+    typedef _Tp* pointer;
+    typedef _Tp& reference;
+    typedef random_access_iterator_tag iterator_category;
+};
+
+template <class _Tp, class _Up, bool = __has_iterator_category<iterator_traits<_Tp> >::value>
+struct __has_iterator_category_convertible_to
+    : public integral_constant<bool, is_convertible<typename iterator_traits<_Tp>::iterator_category, _Up>::value>
+{};
+
+template <class _Tp, class _Up>
+struct __has_iterator_category_convertible_to<_Tp, _Up, false> : public false_type {};
+
+template <class _Tp>
+struct __is_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {};
+
+template <class _Tp>
+struct __is_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {};
+
+template <class _Tp>
+struct __is_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {};
+
+template <class _Tp>
+struct __is_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {};
+
+template<class _Category, class _Tp, class _Distance = ptrdiff_t,
+         class _Pointer = _Tp*, class _Reference = _Tp&>
+struct _LIBCPP_TYPE_VIS_ONLY iterator
+{
+    typedef _Tp        value_type;
+    typedef _Distance  difference_type;
+    typedef _Pointer   pointer;
+    typedef _Reference reference;
+    typedef _Category  iterator_category;
+};
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void __advance(_InputIter& __i,
+             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
+{
+    for (; __n > 0; --__n)
+        ++__i;
+}
+
+template <class _BiDirIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void __advance(_BiDirIter& __i,
+             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
+{
+    if (__n >= 0)
+        for (; __n > 0; --__n)
+            ++__i;
+    else
+        for (; __n < 0; ++__n)
+            --__i;
+}
+
+template <class _RandIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void __advance(_RandIter& __i,
+             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
+{
+   __i += __n;
+}
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void advance(_InputIter& __i,
+             typename iterator_traits<_InputIter>::difference_type __n)
+{
+    __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
+}
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_InputIter>::difference_type
+__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
+{
+    typename iterator_traits<_InputIter>::difference_type __r(0);
+    for (; __first != __last; ++__first)
+        ++__r;
+    return __r;
+}
+
+template <class _RandIter>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_RandIter>::difference_type
+__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
+{
+    return __last - __first;
+}
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_InputIter>::difference_type
+distance(_InputIter __first, _InputIter __last)
+{
+    return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
+}
+
+template <class _ForwardIter>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIter
+next(_ForwardIter __x,
+     typename iterator_traits<_ForwardIter>::difference_type __n = 1,
+     typename enable_if<__is_forward_iterator<_ForwardIter>::value>::type* = 0)
+{
+    _VSTD::advance(__x, __n);
+    return __x;
+}
+
+template <class _BidiretionalIter>
+inline _LIBCPP_INLINE_VISIBILITY
+_BidiretionalIter
+prev(_BidiretionalIter __x,
+     typename iterator_traits<_BidiretionalIter>::difference_type __n = 1,
+     typename enable_if<__is_bidirectional_iterator<_BidiretionalIter>::value>::type* = 0)
+{
+    _VSTD::advance(__x, -__n);
+    return __x;
+}
+
+template <class _Iter>
+class _LIBCPP_TYPE_VIS_ONLY reverse_iterator
+    : public iterator<typename iterator_traits<_Iter>::iterator_category,
+                      typename iterator_traits<_Iter>::value_type,
+                      typename iterator_traits<_Iter>::difference_type,
+                      typename iterator_traits<_Iter>::pointer,
+                      typename iterator_traits<_Iter>::reference>
+{
+private:
+    mutable _Iter __t;
+protected:
+    _Iter current;
+public:
+    typedef _Iter                                            iterator_type;
+    typedef typename iterator_traits<_Iter>::difference_type difference_type;
+    typedef typename iterator_traits<_Iter>::reference       reference;
+    typedef typename iterator_traits<_Iter>::pointer         pointer;
+
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator() : current() {}
+    _LIBCPP_INLINE_VISIBILITY explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY reverse_iterator(const reverse_iterator<_Up>& __u)
+        : __t(__u.base()), current(__u.base()) {}
+    _LIBCPP_INLINE_VISIBILITY _Iter base() const {return current;}
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {__t = current; return *--__t;}
+    _LIBCPP_INLINE_VISIBILITY pointer  operator->() const {return &(operator*());}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator++() {--current; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator++(int)
+        {reverse_iterator __tmp(*this); --current; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator--() {++current; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator--(int)
+        {reverse_iterator __tmp(*this); ++current; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator+ (difference_type __n) const
+        {return reverse_iterator(current - __n);}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator+=(difference_type __n)
+        {current -= __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator- (difference_type __n) const
+        {return reverse_iterator(current + __n);}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator-=(difference_type __n)
+        {current += __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reference         operator[](difference_type __n) const
+        {return current[-__n-1];}
+};
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() == __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() > __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() != __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() < __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() <= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() >= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename reverse_iterator<_Iter1>::difference_type
+operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __y.base() - __x.base();
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Iter>
+operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
+{
+    return reverse_iterator<_Iter>(__x.base() - __n);
+}
+
+template <class _Container>
+class _LIBCPP_TYPE_VIS_ONLY back_insert_iterator
+    : public iterator<output_iterator_tag,
+                      void,
+                      void,
+                      void,
+                      back_insert_iterator<_Container>&>
+{
+protected:
+    _Container* container;
+public:
+    typedef _Container container_type;
+
+    _LIBCPP_INLINE_VISIBILITY explicit back_insert_iterator(_Container& __x) : container(&__x) {}
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(const typename _Container::value_type& __value_)
+        {container->push_back(__value_); return *this;}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(typename _Container::value_type&& __value_)
+        {container->push_back(_VSTD::move(__value_)); return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator  operator++(int) {return *this;}
+};
+
+template <class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+back_insert_iterator<_Container>
+back_inserter(_Container& __x)
+{
+    return back_insert_iterator<_Container>(__x);
+}
+
+template <class _Container>
+class _LIBCPP_TYPE_VIS_ONLY front_insert_iterator
+    : public iterator<output_iterator_tag,
+                      void,
+                      void,
+                      void,
+                      front_insert_iterator<_Container>&>
+{
+protected:
+    _Container* container;
+public:
+    typedef _Container container_type;
+
+    _LIBCPP_INLINE_VISIBILITY explicit front_insert_iterator(_Container& __x) : container(&__x) {}
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(const typename _Container::value_type& __value_)
+        {container->push_front(__value_); return *this;}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(typename _Container::value_type&& __value_)
+        {container->push_front(_VSTD::move(__value_)); return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator  operator++(int) {return *this;}
+};
+
+template <class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+front_insert_iterator<_Container>
+front_inserter(_Container& __x)
+{
+    return front_insert_iterator<_Container>(__x);
+}
+
+template <class _Container>
+class _LIBCPP_TYPE_VIS_ONLY insert_iterator
+    : public iterator<output_iterator_tag,
+                      void,
+                      void,
+                      void,
+                      insert_iterator<_Container>&>
+{
+protected:
+    _Container* container;
+    typename _Container::iterator iter;
+public:
+    typedef _Container container_type;
+
+    _LIBCPP_INLINE_VISIBILITY insert_iterator(_Container& __x, typename _Container::iterator __i)
+        : container(&__x), iter(__i) {}
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(const typename _Container::value_type& __value_)
+        {iter = container->insert(iter, __value_); ++iter; return *this;}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(typename _Container::value_type&& __value_)
+        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator*()        {return *this;}
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++()       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++(int)    {return *this;}
+};
+
+template <class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+insert_iterator<_Container>
+inserter(_Container& __x, typename _Container::iterator __i)
+{
+    return insert_iterator<_Container>(__x, __i);
+}
+
+template <class _Tp, class _CharT = char,
+          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
+class _LIBCPP_TYPE_VIS_ONLY istream_iterator
+    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
+{
+public:
+    typedef _CharT char_type;
+    typedef _Traits traits_type;
+    typedef basic_istream<_CharT,_Traits> istream_type;
+private:
+    istream_type* __in_stream_;
+    _Tp __value_;
+public:
+    _LIBCPP_INLINE_VISIBILITY istream_iterator() : __in_stream_(0) {}
+    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(&__s)
+        {
+            if (!(*__in_stream_ >> __value_))
+                __in_stream_ = 0;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
+    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return &(operator*());}
+    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
+        {
+            if (!(*__in_stream_ >> __value_))
+                __in_stream_ = 0;
+            return *this;
+        }
+    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
+        {istream_iterator __t(*this); ++(*this); return __t;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const istream_iterator& __x, const istream_iterator& __y)
+        {return __x.__in_stream_ == __y.__in_stream_;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const istream_iterator& __x, const istream_iterator& __y)
+        {return !(__x == __y);}
+};
+
+template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY ostream_iterator
+    : public iterator<output_iterator_tag, void, void, void, void>
+{
+public:
+    typedef _CharT char_type;
+    typedef _Traits traits_type;
+    typedef basic_ostream<_CharT,_Traits> ostream_type;
+private:
+    ostream_type* __out_stream_;
+    const char_type* __delim_;
+public:
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s)
+        : __out_stream_(&__s), __delim_(0) {}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter)
+        : __out_stream_(&__s), __delim_(__delimiter) {}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
+        {
+            *__out_stream_ << __value_;
+            if (__delim_)
+                *__out_stream_ << __delim_;
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
+};
+
+template<class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY istreambuf_iterator
+    : public iterator<input_iterator_tag, _CharT,
+                      typename _Traits::off_type, _CharT*,
+                      _CharT>
+{
+public:
+    typedef _CharT                          char_type;
+    typedef _Traits                         traits_type;
+    typedef typename _Traits::int_type      int_type;
+    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
+    typedef basic_istream<_CharT,_Traits>   istream_type;
+private:
+    mutable streambuf_type* __sbuf_;
+
+    class __proxy
+    {
+        char_type __keep_;
+        streambuf_type* __sbuf_;
+        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
+            : __keep_(__c), __sbuf_(__s) {}
+        friend class istreambuf_iterator;
+    public:
+        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
+    };
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool __test_for_eof() const
+    {
+        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
+            __sbuf_ = 0;
+        return __sbuf_ == 0;
+    }
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(0) {}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
+        : __sbuf_(__s.rdbuf()) {}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
+        : __sbuf_(__s) {}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
+        : __sbuf_(__p.__sbuf_) {}
+
+    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
+        {return static_cast<char_type>(__sbuf_->sgetc());}
+    _LIBCPP_INLINE_VISIBILITY char_type* operator->() const {return nullptr;}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
+        {
+            __sbuf_->sbumpc();
+            return *this;
+        }
+    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
+        {
+            return __proxy(__sbuf_->sbumpc(), __sbuf_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
+        {return __test_for_eof() == __b.__test_for_eof();}
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
+                const istreambuf_iterator<_CharT,_Traits>& __b)
+                {return __a.equal(__b);}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
+                const istreambuf_iterator<_CharT,_Traits>& __b)
+                {return !__a.equal(__b);}
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY ostreambuf_iterator
+    : public iterator<output_iterator_tag, void, void, void, void>
+{
+public:
+    typedef _CharT                          char_type;
+    typedef _Traits                         traits_type;
+    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
+    typedef basic_ostream<_CharT,_Traits>   ostream_type;
+private:
+    streambuf_type* __sbuf_;
+public:
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
+        : __sbuf_(__s.rdbuf()) {}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
+        : __sbuf_(__s) {}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
+        {
+            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
+                __sbuf_ = 0;
+            return *this;
+        }
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
+    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == 0;}
+
+#if !defined(__APPLE__) || \
+    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
+    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
+
+    template <class _Ch, class _Tr>
+    friend
+    _LIBCPP_HIDDEN
+    ostreambuf_iterator<_Ch, _Tr>
+    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
+                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
+                     ios_base& __iob, _Ch __fl);
+#endif
+};
+
+template <class _Iter>
+class _LIBCPP_TYPE_VIS_ONLY move_iterator
+{
+private:
+    _Iter __i;
+public:
+    typedef _Iter                                            iterator_type;
+    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
+    typedef typename iterator_traits<iterator_type>::value_type value_type;
+    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
+    typedef typename iterator_traits<iterator_type>::pointer pointer;
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    typedef value_type&& reference;
+#else
+    typedef typename iterator_traits<iterator_type>::reference reference;
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY move_iterator() : __i() {}
+    _LIBCPP_INLINE_VISIBILITY explicit move_iterator(_Iter __x) : __i(__x) {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY move_iterator(const move_iterator<_Up>& __u)
+        : __i(__u.base()) {}
+    _LIBCPP_INLINE_VISIBILITY _Iter base() const {return __i;}
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {
+      return static_cast<reference>(*__i);
+    }
+    _LIBCPP_INLINE_VISIBILITY pointer  operator->() const {
+      typename iterator_traits<iterator_type>::reference __ref = *__i;
+      return &__ref;
+    }
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator++() {++__i; return *this;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator++(int)
+        {move_iterator __tmp(*this); ++__i; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator--() {--__i; return *this;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator--(int)
+        {move_iterator __tmp(*this); --__i; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator+ (difference_type __n) const
+        {return move_iterator(__i + __n);}
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator+=(difference_type __n)
+        {__i += __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator- (difference_type __n) const
+        {return move_iterator(__i - __n);}
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator-=(difference_type __n)
+        {__i -= __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reference         operator[](difference_type __n) const
+    {
+      return static_cast<reference>(__i[__n]);
+    }
+};
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() == __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() < __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() != __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() > __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() >= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() <= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename move_iterator<_Iter1>::difference_type
+operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() - __y.base();
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+move_iterator<_Iter>
+operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
+{
+    return move_iterator<_Iter>(__x.base() + __n);
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+move_iterator<_Iter>
+make_move_iterator(_Iter __i)
+{
+    return move_iterator<_Iter>(__i);
+}
+
+// __wrap_iter
+
+template <class _Iter> class __wrap_iter;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+typename __wrap_iter<_Iter1>::difference_type
+operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter>
+_LIBCPP_INLINE_VISIBILITY
+__wrap_iter<_Iter>
+operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT;
+
+template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY copy(_Ip, _Ip, _Op);
+template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY copy_backward(_B1, _B1, _B2);
+template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY move(_Ip, _Ip, _Op);
+template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY move_backward(_B1, _B1, _B2);
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_trivially_copy_assignable<_Tp>::value,
+    _Tp*
+>::type
+__unwrap_iter(__wrap_iter<_Tp*>);
+
+template <class _Iter>
+class __wrap_iter
+{
+public:
+    typedef _Iter                                                      iterator_type;
+    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
+    typedef typename iterator_traits<iterator_type>::value_type        value_type;
+    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
+    typedef typename iterator_traits<iterator_type>::pointer           pointer;
+    typedef typename iterator_traits<iterator_type>::reference         reference;
+private:
+    iterator_type __i;
+public:
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+                : __i{}
+#endif
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY __wrap_iter(const __wrap_iter<_Up>& __u,
+        typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = 0) _NOEXCEPT
+        : __i(__u.base())
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__iterator_copy(this, &__u);
+#endif
+    }
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    __wrap_iter(const __wrap_iter& __x)
+        : __i(__x.base())
+    {
+        __get_db()->__iterator_copy(this, &__x);
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __wrap_iter& operator=(const __wrap_iter& __x)
+    {
+        if (this != &__x)
+        {
+            __get_db()->__iterator_copy(this, &__x);
+            __i = __x.__i;
+        }
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    ~__wrap_iter()
+    {
+        __get_db()->__erase_i(this);
+    }
+#endif
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable iterator");
+#endif
+        return *__i;
+    }
+    _LIBCPP_INLINE_VISIBILITY pointer  operator->() const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable iterator");
+#endif
+        return (pointer)&reinterpret_cast<const volatile char&>(*__i);
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator++() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable iterator");
+#endif
+        ++__i;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator++(int) _NOEXCEPT
+        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator--() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
+                       "Attempted to decrement non-decrementable iterator");
+#endif
+        --__i;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator--(int) _NOEXCEPT
+        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
+        {__wrap_iter __w(*this); __w += __n; return __w;}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
+                   "Attempted to add/subtract iterator outside of valid range");
+#endif
+        __i += __n;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
+        {return *this + (-__n);}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
+        {*this += -__n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reference        operator[](difference_type __n) const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
+                   "Attempted to subscript iterator outside of valid range");
+#endif
+        return __i[__n];
+    }
+
+    _LIBCPP_INLINE_VISIBILITY iterator_type base() const _NOEXCEPT {return __i;}
+
+private:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
+    {
+        __get_db()->__insert_ic(this, __p);
+    }
+#else
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter(iterator_type __x) _NOEXCEPT : __i(__x) {}
+#endif
+
+    template <class _Up> friend class __wrap_iter;
+    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
+    template <class _Tp, class _Alloc> friend class vector;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    typename __wrap_iter<_Iter1>::difference_type
+    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1>
+    friend
+    __wrap_iter<_Iter1>
+    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT;
+
+    template <class _Ip, class _Op> friend _Op copy(_Ip, _Ip, _Op);
+    template <class _B1, class _B2> friend _B2 copy_backward(_B1, _B1, _B2);
+    template <class _Ip, class _Op> friend _Op move(_Ip, _Ip, _Op);
+    template <class _B1, class _B2> friend _B2 move_backward(_B1, _B1, _B2);
+
+    template <class _Tp>
+    friend
+    typename enable_if
+    <
+        is_trivially_copy_assignable<_Tp>::value,
+        _Tp*
+    >::type
+    __unwrap_iter(__wrap_iter<_Tp*>);
+};
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return __x.base() == __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
+                   "Attempted to compare incomparable iterators");
+#endif
+    return __x.base() < __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return !(__x == __y);
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return __y < __x;
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return !(__x < __y);
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return !(__y < __x);
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return !(__x == __y);
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return __y < __x;
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return !(__x < __y);
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return !(__y < __x);
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __wrap_iter<_Iter1>::difference_type
+operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
+                   "Attempted to subtract incompatible iterators");
+#endif
+    return __x.base() - __y.base();
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+__wrap_iter<_Iter>
+operator+(typename __wrap_iter<_Iter>::difference_type __n,
+          __wrap_iter<_Iter> __x) _NOEXCEPT
+{
+    __x += __n;
+    return __x;
+}
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_TRAILING_RETURN)
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+begin(_Cp& __c) -> decltype(__c.begin())
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+begin(const _Cp& __c) -> decltype(__c.begin())
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+end(_Cp& __c) -> decltype(__c.end())
+{
+    return __c.end();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+end(const _Cp& __c) -> decltype(__c.end())
+{
+    return __c.end();
+}
+
+#if _LIBCPP_STD_VER > 11
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto cbegin(const _Cp& __c) -> decltype(begin(__c))
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto cend(const _Cp& __c) -> decltype(end(__c))
+{
+    return __c.end();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
+{
+    return __c.rbegin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
+{
+    return __c.rbegin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rend(_Cp& __c) -> decltype(__c.rend())
+{
+    return __c.rend();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rend(const _Cp& __c) -> decltype(__c.rend())
+{
+    return __c.rend();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto crbegin(const _Cp& __c) -> decltype(rbegin(__c))
+{
+    return rbegin(__c);
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto crend(const _Cp& __c) -> decltype(rend(__c))
+{
+    return rend(__c);
+}
+
+#endif
+
+
+#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_TRAILING_RETURN)
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::iterator
+begin(_Cp& __c)
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::const_iterator
+begin(const _Cp& __c)
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::iterator
+end(_Cp& __c)
+{
+    return __c.end();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::const_iterator
+end(const _Cp& __c)
+{
+    return __c.end();
+}
+
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_TRAILING_RETURN)
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+begin(_Tp (&__array)[_Np])
+{
+    return __array;
+}
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+end(_Tp (&__array)[_Np])
+{
+    return __array + _Np;
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
+{
+    return reverse_iterator<_Tp*>(__array + _Np);
+}
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
+{
+    return reverse_iterator<_Tp*>(__array);
+}
+
+template <class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
+{
+    return reverse_iterator<const _Ep*>(__il.end());
+}
+
+template <class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
+{
+    return reverse_iterator<const _Ep*>(__il.begin());
+}
+
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_ITERATOR