Restoring authorship annotation for Andrey Khalyavin <halyavin@gmail.com>. Commit 1 of 2.

1 files changed, 2513 insertions, 2513 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/__tree b/contrib/libs/cxxsupp/libcxx/include/__tree
index f3f2e8d15f..f7d4abe97c 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__tree
+++ b/contrib/libs/cxxsupp/libcxx/include/__tree
@@ -1,33 +1,33 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
+// -*- C++ -*- 
+//===----------------------------------------------------------------------===// 
+// 
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___TREE
-#define _LIBCPP___TREE
-
-#include <__config>
-#include <__utility/forward.h>
-#include <algorithm>
-#include <iterator>
-#include <limits>
-#include <memory>
-#include <stdexcept>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
+// 
+//===----------------------------------------------------------------------===// 
+ 
+#ifndef _LIBCPP___TREE 
+#define _LIBCPP___TREE 
+ 
+#include <__config> 
+#include <__utility/forward.h> 
+#include <algorithm> 
+#include <iterator> 
+#include <limits> 
+#include <memory> 
+#include <stdexcept> 
+ 
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 
+#pragma GCC system_header 
+#endif 
+ 
+_LIBCPP_PUSH_MACROS 
+#include <__undef_macros> 
+ 
+ 
+_LIBCPP_BEGIN_NAMESPACE_STD 
+ 
 #if defined(__GNUC__) && !defined(__clang__) // gcc.gnu.org/PR37804
 template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS map;
 template <class, class, class, class> class _LIBCPP_TEMPLATE_VIS multimap;
@@ -35,768 +35,768 @@ template <class, class, class> class _LIBCPP_TEMPLATE_VIS set;
 template <class, class, class> class _LIBCPP_TEMPLATE_VIS multiset;
 #endif
 
-template <class _Tp, class _Compare, class _Allocator> class __tree;
-template <class _Tp, class _NodePtr, class _DiffType>
-    class _LIBCPP_TEMPLATE_VIS __tree_iterator;
-template <class _Tp, class _ConstNodePtr, class _DiffType>
-    class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
-
-template <class _Pointer> class __tree_end_node;
-template <class _VoidPtr> class __tree_node_base;
-template <class _Tp, class _VoidPtr> class __tree_node;
-
-template <class _Key, class _Value>
-struct __value_type;
-
-template <class _Allocator> class __map_node_destructor;
-template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_iterator;
-template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
-
-/*
-
-_NodePtr algorithms
-
-The algorithms taking _NodePtr are red black tree algorithms.  Those
-algorithms taking a parameter named __root should assume that __root
-points to a proper red black tree (unless otherwise specified).
-
-Each algorithm herein assumes that __root->__parent_ points to a non-null
-structure which has a member __left_ which points back to __root.  No other
-member is read or written to at __root->__parent_.
-
-__root->__parent_ will be referred to below (in comments only) as end_node.
-end_node->__left_ is an externably accessible lvalue for __root, and can be
-changed by node insertion and removal (without explicit reference to end_node).
-
-All nodes (with the exception of end_node), even the node referred to as
-__root, have a non-null __parent_ field.
-
-*/
-
-// Returns:  true if __x is a left child of its parent, else false
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-__tree_is_left_child(_NodePtr __x) _NOEXCEPT
-{
-    return __x == __x->__parent_->__left_;
-}
-
-// Determines if the subtree rooted at __x is a proper red black subtree.  If
-//    __x is a proper subtree, returns the black height (null counts as 1).  If
-//    __x is an improper subtree, returns 0.
-template <class _NodePtr>
-unsigned
-__tree_sub_invariant(_NodePtr __x)
-{
-    if (__x == nullptr)
-        return 1;
-    // parent consistency checked by caller
-    // check __x->__left_ consistency
-    if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x)
-        return 0;
-    // check __x->__right_ consistency
-    if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x)
-        return 0;
-    // check __x->__left_ != __x->__right_ unless both are nullptr
-    if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr)
-        return 0;
-    // If this is red, neither child can be red
-    if (!__x->__is_black_)
-    {
-        if (__x->__left_ && !__x->__left_->__is_black_)
-            return 0;
-        if (__x->__right_ && !__x->__right_->__is_black_)
-            return 0;
-    }
-    unsigned __h = _VSTD::__tree_sub_invariant(__x->__left_);
-    if (__h == 0)
-        return 0;  // invalid left subtree
-    if (__h != _VSTD::__tree_sub_invariant(__x->__right_))
-        return 0;  // invalid or different height right subtree
-    return __h + __x->__is_black_;  // return black height of this node
-}
-
-// Determines if the red black tree rooted at __root is a proper red black tree.
-//    __root == nullptr is a proper tree.  Returns true is __root is a proper
-//    red black tree, else returns false.
-template <class _NodePtr>
-bool
-__tree_invariant(_NodePtr __root)
-{
-    if (__root == nullptr)
-        return true;
-    // check __x->__parent_ consistency
-    if (__root->__parent_ == nullptr)
-        return false;
-    if (!_VSTD::__tree_is_left_child(__root))
-        return false;
-    // root must be black
-    if (!__root->__is_black_)
-        return false;
-    // do normal node checks
-    return _VSTD::__tree_sub_invariant(__root) != 0;
-}
-
-// Returns:  pointer to the left-most node under __x.
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_NodePtr
-__tree_min(_NodePtr __x) _NOEXCEPT
-{
-    while (__x->__left_ != nullptr)
-        __x = __x->__left_;
-    return __x;
-}
-
-// Returns:  pointer to the right-most node under __x.
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_NodePtr
-__tree_max(_NodePtr __x) _NOEXCEPT
-{
-    while (__x->__right_ != nullptr)
-        __x = __x->__right_;
-    return __x;
-}
-
-// Returns:  pointer to the next in-order node after __x.
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-_NodePtr
-__tree_next(_NodePtr __x) _NOEXCEPT
-{
-    if (__x->__right_ != nullptr)
-        return _VSTD::__tree_min(__x->__right_);
-    while (!_VSTD::__tree_is_left_child(__x))
-        __x = __x->__parent_unsafe();
-    return __x->__parent_unsafe();
-}
-
-template <class _EndNodePtr, class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_EndNodePtr
-__tree_next_iter(_NodePtr __x) _NOEXCEPT
-{
-    if (__x->__right_ != nullptr)
-        return static_cast<_EndNodePtr>(_VSTD::__tree_min(__x->__right_));
-    while (!_VSTD::__tree_is_left_child(__x))
-        __x = __x->__parent_unsafe();
-    return static_cast<_EndNodePtr>(__x->__parent_);
-}
-
-// Returns:  pointer to the previous in-order node before __x.
-// Precondition:  __x != nullptr.
-// Note: __x may be the end node.
-template <class _NodePtr, class _EndNodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_NodePtr
-__tree_prev_iter(_EndNodePtr __x) _NOEXCEPT
-{
-    if (__x->__left_ != nullptr)
-        return _VSTD::__tree_max(__x->__left_);
-    _NodePtr __xx = static_cast<_NodePtr>(__x);
-    while (_VSTD::__tree_is_left_child(__xx))
-        __xx = __xx->__parent_unsafe();
-    return __xx->__parent_unsafe();
-}
-
-// Returns:  pointer to a node which has no children
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-_NodePtr
-__tree_leaf(_NodePtr __x) _NOEXCEPT
-{
-    while (true)
-    {
-        if (__x->__left_ != nullptr)
-        {
-            __x = __x->__left_;
-            continue;
-        }
-        if (__x->__right_ != nullptr)
-        {
-            __x = __x->__right_;
-            continue;
-        }
-        break;
-    }
-    return __x;
-}
-
-// Effects:  Makes __x->__right_ the subtree root with __x as its left child
-//           while preserving in-order order.
-// Precondition:  __x->__right_ != nullptr
-template <class _NodePtr>
-void
-__tree_left_rotate(_NodePtr __x) _NOEXCEPT
-{
-    _NodePtr __y = __x->__right_;
-    __x->__right_ = __y->__left_;
-    if (__x->__right_ != nullptr)
-        __x->__right_->__set_parent(__x);
-    __y->__parent_ = __x->__parent_;
-    if (_VSTD::__tree_is_left_child(__x))
-        __x->__parent_->__left_ = __y;
-    else
-        __x->__parent_unsafe()->__right_ = __y;
-    __y->__left_ = __x;
-    __x->__set_parent(__y);
-}
-
-// Effects:  Makes __x->__left_ the subtree root with __x as its right child
-//           while preserving in-order order.
-// Precondition:  __x->__left_ != nullptr
-template <class _NodePtr>
-void
-__tree_right_rotate(_NodePtr __x) _NOEXCEPT
-{
-    _NodePtr __y = __x->__left_;
-    __x->__left_ = __y->__right_;
-    if (__x->__left_ != nullptr)
-        __x->__left_->__set_parent(__x);
-    __y->__parent_ = __x->__parent_;
-    if (_VSTD::__tree_is_left_child(__x))
-        __x->__parent_->__left_ = __y;
-    else
-        __x->__parent_unsafe()->__right_ = __y;
-    __y->__right_ = __x;
-    __x->__set_parent(__y);
-}
-
-// Effects:  Rebalances __root after attaching __x to a leaf.
-// Precondition:  __root != nulptr && __x != nullptr.
-//                __x has no children.
-//                __x == __root or == a direct or indirect child of __root.
-//                If __x were to be unlinked from __root (setting __root to
-//                  nullptr if __root == __x), __tree_invariant(__root) == true.
-// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_
-//                may be different than the value passed in as __root.
-template <class _NodePtr>
-void
-__tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
-{
-    __x->__is_black_ = __x == __root;
-    while (__x != __root && !__x->__parent_unsafe()->__is_black_)
-    {
-        // __x->__parent_ != __root because __x->__parent_->__is_black == false
-        if (_VSTD::__tree_is_left_child(__x->__parent_unsafe()))
-        {
-            _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_;
-            if (__y != nullptr && !__y->__is_black_)
-            {
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = __x == __root;
-                __y->__is_black_ = true;
-            }
-            else
-            {
-                if (!_VSTD::__tree_is_left_child(__x))
-                {
-                    __x = __x->__parent_unsafe();
-                    _VSTD::__tree_left_rotate(__x);
-                }
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = false;
-                _VSTD::__tree_right_rotate(__x);
-                break;
-            }
-        }
-        else
-        {
-            _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_;
-            if (__y != nullptr && !__y->__is_black_)
-            {
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = __x == __root;
-                __y->__is_black_ = true;
-            }
-            else
-            {
-                if (_VSTD::__tree_is_left_child(__x))
-                {
-                    __x = __x->__parent_unsafe();
-                    _VSTD::__tree_right_rotate(__x);
-                }
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = false;
-                _VSTD::__tree_left_rotate(__x);
-                break;
-            }
-        }
-    }
-}
-
-// Precondition:  __root != nullptr && __z != nullptr.
-//                __tree_invariant(__root) == true.
-//                __z == __root or == a direct or indirect child of __root.
-// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed.
-// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_
-//                nor any of its children refer to __z.  end_node->__left_
-//                may be different than the value passed in as __root.
-template <class _NodePtr>
-void
-__tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
-{
-    // __z will be removed from the tree.  Client still needs to destruct/deallocate it
-    // __y is either __z, or if __z has two children, __tree_next(__z).
-    // __y will have at most one child.
-    // __y will be the initial hole in the tree (make the hole at a leaf)
-    _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ?
-                    __z : _VSTD::__tree_next(__z);
-    // __x is __y's possibly null single child
-    _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_;
-    // __w is __x's possibly null uncle (will become __x's sibling)
-    _NodePtr __w = nullptr;
-    // link __x to __y's parent, and find __w
-    if (__x != nullptr)
-        __x->__parent_ = __y->__parent_;
-    if (_VSTD::__tree_is_left_child(__y))
-    {
-        __y->__parent_->__left_ = __x;
-        if (__y != __root)
-            __w = __y->__parent_unsafe()->__right_;
-        else
-            __root = __x;  // __w == nullptr
-    }
-    else
-    {
-        __y->__parent_unsafe()->__right_ = __x;
-        // __y can't be root if it is a right child
-        __w = __y->__parent_->__left_;
-    }
-    bool __removed_black = __y->__is_black_;
-    // If we didn't remove __z, do so now by splicing in __y for __z,
-    //    but copy __z's color.  This does not impact __x or __w.
-    if (__y != __z)
-    {
-        // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr
-        __y->__parent_ = __z->__parent_;
-        if (_VSTD::__tree_is_left_child(__z))
-            __y->__parent_->__left_ = __y;
-        else
-            __y->__parent_unsafe()->__right_ = __y;
-        __y->__left_ = __z->__left_;
-        __y->__left_->__set_parent(__y);
-        __y->__right_ = __z->__right_;
-        if (__y->__right_ != nullptr)
-            __y->__right_->__set_parent(__y);
-        __y->__is_black_ = __z->__is_black_;
-        if (__root == __z)
-            __root = __y;
-    }
-    // There is no need to rebalance if we removed a red, or if we removed
-    //     the last node.
-    if (__removed_black && __root != nullptr)
-    {
-        // Rebalance:
-        // __x has an implicit black color (transferred from the removed __y)
-        //    associated with it, no matter what its color is.
-        // If __x is __root (in which case it can't be null), it is supposed
-        //    to be black anyway, and if it is doubly black, then the double
-        //    can just be ignored.
-        // If __x is red (in which case it can't be null), then it can absorb
-        //    the implicit black just by setting its color to black.
-        // Since __y was black and only had one child (which __x points to), __x
-        //   is either red with no children, else null, otherwise __y would have
-        //   different black heights under left and right pointers.
-        // if (__x == __root || __x != nullptr && !__x->__is_black_)
-        if (__x != nullptr)
-            __x->__is_black_ = true;
-        else
-        {
-            //  Else __x isn't root, and is "doubly black", even though it may
-            //     be null.  __w can not be null here, else the parent would
-            //     see a black height >= 2 on the __x side and a black height
-            //     of 1 on the __w side (__w must be a non-null black or a red
-            //     with a non-null black child).
-            while (true)
-            {
-                if (!_VSTD::__tree_is_left_child(__w))  // if x is left child
-                {
-                    if (!__w->__is_black_)
-                    {
-                        __w->__is_black_ = true;
-                        __w->__parent_unsafe()->__is_black_ = false;
-                        _VSTD::__tree_left_rotate(__w->__parent_unsafe());
-                        // __x is still valid
-                        // reset __root only if necessary
-                        if (__root == __w->__left_)
-                            __root = __w;
-                        // reset sibling, and it still can't be null
-                        __w = __w->__left_->__right_;
-                    }
-                    // __w->__is_black_ is now true, __w may have null children
-                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
-                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
-                    {
-                        __w->__is_black_ = false;
-                        __x = __w->__parent_unsafe();
-                        // __x can no longer be null
-                        if (__x == __root || !__x->__is_black_)
-                        {
-                            __x->__is_black_ = true;
-                            break;
-                        }
-                        // reset sibling, and it still can't be null
-                        __w = _VSTD::__tree_is_left_child(__x) ?
-                                    __x->__parent_unsafe()->__right_ :
-                                    __x->__parent_->__left_;
-                        // continue;
-                    }
-                    else  // __w has a red child
-                    {
-                        if (__w->__right_ == nullptr || __w->__right_->__is_black_)
-                        {
-                            // __w left child is non-null and red
-                            __w->__left_->__is_black_ = true;
-                            __w->__is_black_ = false;
-                            _VSTD::__tree_right_rotate(__w);
-                            // __w is known not to be root, so root hasn't changed
-                            // reset sibling, and it still can't be null
-                            __w = __w->__parent_unsafe();
-                        }
-                        // __w has a right red child, left child may be null
-                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
-                        __w->__parent_unsafe()->__is_black_ = true;
-                        __w->__right_->__is_black_ = true;
-                        _VSTD::__tree_left_rotate(__w->__parent_unsafe());
-                        break;
-                    }
-                }
-                else
-                {
-                    if (!__w->__is_black_)
-                    {
-                        __w->__is_black_ = true;
-                        __w->__parent_unsafe()->__is_black_ = false;
-                        _VSTD::__tree_right_rotate(__w->__parent_unsafe());
-                        // __x is still valid
-                        // reset __root only if necessary
-                        if (__root == __w->__right_)
-                            __root = __w;
-                        // reset sibling, and it still can't be null
-                        __w = __w->__right_->__left_;
-                    }
-                    // __w->__is_black_ is now true, __w may have null children
-                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
-                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
-                    {
-                        __w->__is_black_ = false;
-                        __x = __w->__parent_unsafe();
-                        // __x can no longer be null
-                        if (!__x->__is_black_ || __x == __root)
-                        {
-                            __x->__is_black_ = true;
-                            break;
-                        }
-                        // reset sibling, and it still can't be null
-                        __w = _VSTD::__tree_is_left_child(__x) ?
-                                    __x->__parent_unsafe()->__right_ :
-                                    __x->__parent_->__left_;
-                        // continue;
-                    }
-                    else  // __w has a red child
-                    {
-                        if (__w->__left_ == nullptr || __w->__left_->__is_black_)
-                        {
-                            // __w right child is non-null and red
-                            __w->__right_->__is_black_ = true;
-                            __w->__is_black_ = false;
-                            _VSTD::__tree_left_rotate(__w);
-                            // __w is known not to be root, so root hasn't changed
-                            // reset sibling, and it still can't be null
-                            __w = __w->__parent_unsafe();
-                        }
-                        // __w has a left red child, right child may be null
-                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
-                        __w->__parent_unsafe()->__is_black_ = true;
-                        __w->__left_->__is_black_ = true;
-                        _VSTD::__tree_right_rotate(__w->__parent_unsafe());
-                        break;
-                    }
-                }
-            }
-        }
-    }
-}
-
-// node traits
-
-
-template <class _Tp>
-struct __is_tree_value_type_imp : false_type {};
-
-template <class _Key, class _Value>
+template <class _Tp, class _Compare, class _Allocator> class __tree; 
+template <class _Tp, class _NodePtr, class _DiffType> 
+    class _LIBCPP_TEMPLATE_VIS __tree_iterator; 
+template <class _Tp, class _ConstNodePtr, class _DiffType> 
+    class _LIBCPP_TEMPLATE_VIS __tree_const_iterator; 
+ 
+template <class _Pointer> class __tree_end_node; 
+template <class _VoidPtr> class __tree_node_base; 
+template <class _Tp, class _VoidPtr> class __tree_node; 
+ 
+template <class _Key, class _Value> 
+struct __value_type; 
+ 
+template <class _Allocator> class __map_node_destructor; 
+template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_iterator; 
+template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_const_iterator; 
+ 
+/* 
+ 
+_NodePtr algorithms 
+ 
+The algorithms taking _NodePtr are red black tree algorithms.  Those 
+algorithms taking a parameter named __root should assume that __root 
+points to a proper red black tree (unless otherwise specified). 
+ 
+Each algorithm herein assumes that __root->__parent_ points to a non-null 
+structure which has a member __left_ which points back to __root.  No other 
+member is read or written to at __root->__parent_. 
+ 
+__root->__parent_ will be referred to below (in comments only) as end_node. 
+end_node->__left_ is an externably accessible lvalue for __root, and can be 
+changed by node insertion and removal (without explicit reference to end_node). 
+ 
+All nodes (with the exception of end_node), even the node referred to as 
+__root, have a non-null __parent_ field. 
+ 
+*/ 
+ 
+// Returns:  true if __x is a left child of its parent, else false 
+// Precondition:  __x != nullptr. 
+template <class _NodePtr> 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+__tree_is_left_child(_NodePtr __x) _NOEXCEPT 
+{ 
+    return __x == __x->__parent_->__left_; 
+} 
+ 
+// Determines if the subtree rooted at __x is a proper red black subtree.  If 
+//    __x is a proper subtree, returns the black height (null counts as 1).  If 
+//    __x is an improper subtree, returns 0. 
+template <class _NodePtr> 
+unsigned 
+__tree_sub_invariant(_NodePtr __x) 
+{ 
+    if (__x == nullptr) 
+        return 1; 
+    // parent consistency checked by caller 
+    // check __x->__left_ consistency 
+    if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x) 
+        return 0; 
+    // check __x->__right_ consistency 
+    if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x) 
+        return 0; 
+    // check __x->__left_ != __x->__right_ unless both are nullptr 
+    if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr) 
+        return 0; 
+    // If this is red, neither child can be red 
+    if (!__x->__is_black_) 
+    { 
+        if (__x->__left_ && !__x->__left_->__is_black_) 
+            return 0; 
+        if (__x->__right_ && !__x->__right_->__is_black_) 
+            return 0; 
+    } 
+    unsigned __h = _VSTD::__tree_sub_invariant(__x->__left_); 
+    if (__h == 0) 
+        return 0;  // invalid left subtree 
+    if (__h != _VSTD::__tree_sub_invariant(__x->__right_)) 
+        return 0;  // invalid or different height right subtree 
+    return __h + __x->__is_black_;  // return black height of this node 
+} 
+ 
+// Determines if the red black tree rooted at __root is a proper red black tree. 
+//    __root == nullptr is a proper tree.  Returns true is __root is a proper 
+//    red black tree, else returns false. 
+template <class _NodePtr> 
+bool 
+__tree_invariant(_NodePtr __root) 
+{ 
+    if (__root == nullptr) 
+        return true; 
+    // check __x->__parent_ consistency 
+    if (__root->__parent_ == nullptr) 
+        return false; 
+    if (!_VSTD::__tree_is_left_child(__root)) 
+        return false; 
+    // root must be black 
+    if (!__root->__is_black_) 
+        return false; 
+    // do normal node checks 
+    return _VSTD::__tree_sub_invariant(__root) != 0; 
+} 
+ 
+// Returns:  pointer to the left-most node under __x. 
+// Precondition:  __x != nullptr. 
+template <class _NodePtr> 
+inline _LIBCPP_INLINE_VISIBILITY 
+_NodePtr 
+__tree_min(_NodePtr __x) _NOEXCEPT 
+{ 
+    while (__x->__left_ != nullptr) 
+        __x = __x->__left_; 
+    return __x; 
+} 
+ 
+// Returns:  pointer to the right-most node under __x. 
+// Precondition:  __x != nullptr. 
+template <class _NodePtr> 
+inline _LIBCPP_INLINE_VISIBILITY 
+_NodePtr 
+__tree_max(_NodePtr __x) _NOEXCEPT 
+{ 
+    while (__x->__right_ != nullptr) 
+        __x = __x->__right_; 
+    return __x; 
+} 
+ 
+// Returns:  pointer to the next in-order node after __x. 
+// Precondition:  __x != nullptr. 
+template <class _NodePtr> 
+_NodePtr 
+__tree_next(_NodePtr __x) _NOEXCEPT 
+{ 
+    if (__x->__right_ != nullptr) 
+        return _VSTD::__tree_min(__x->__right_); 
+    while (!_VSTD::__tree_is_left_child(__x)) 
+        __x = __x->__parent_unsafe(); 
+    return __x->__parent_unsafe(); 
+} 
+ 
+template <class _EndNodePtr, class _NodePtr> 
+inline _LIBCPP_INLINE_VISIBILITY 
+_EndNodePtr 
+__tree_next_iter(_NodePtr __x) _NOEXCEPT 
+{ 
+    if (__x->__right_ != nullptr) 
+        return static_cast<_EndNodePtr>(_VSTD::__tree_min(__x->__right_)); 
+    while (!_VSTD::__tree_is_left_child(__x)) 
+        __x = __x->__parent_unsafe(); 
+    return static_cast<_EndNodePtr>(__x->__parent_); 
+} 
+ 
+// Returns:  pointer to the previous in-order node before __x. 
+// Precondition:  __x != nullptr. 
+// Note: __x may be the end node. 
+template <class _NodePtr, class _EndNodePtr> 
+inline _LIBCPP_INLINE_VISIBILITY 
+_NodePtr 
+__tree_prev_iter(_EndNodePtr __x) _NOEXCEPT 
+{ 
+    if (__x->__left_ != nullptr) 
+        return _VSTD::__tree_max(__x->__left_); 
+    _NodePtr __xx = static_cast<_NodePtr>(__x); 
+    while (_VSTD::__tree_is_left_child(__xx)) 
+        __xx = __xx->__parent_unsafe(); 
+    return __xx->__parent_unsafe(); 
+} 
+ 
+// Returns:  pointer to a node which has no children 
+// Precondition:  __x != nullptr. 
+template <class _NodePtr> 
+_NodePtr 
+__tree_leaf(_NodePtr __x) _NOEXCEPT 
+{ 
+    while (true) 
+    { 
+        if (__x->__left_ != nullptr) 
+        { 
+            __x = __x->__left_; 
+            continue; 
+        } 
+        if (__x->__right_ != nullptr) 
+        { 
+            __x = __x->__right_; 
+            continue; 
+        } 
+        break; 
+    } 
+    return __x; 
+} 
+ 
+// Effects:  Makes __x->__right_ the subtree root with __x as its left child 
+//           while preserving in-order order. 
+// Precondition:  __x->__right_ != nullptr 
+template <class _NodePtr> 
+void 
+__tree_left_rotate(_NodePtr __x) _NOEXCEPT 
+{ 
+    _NodePtr __y = __x->__right_; 
+    __x->__right_ = __y->__left_; 
+    if (__x->__right_ != nullptr) 
+        __x->__right_->__set_parent(__x); 
+    __y->__parent_ = __x->__parent_; 
+    if (_VSTD::__tree_is_left_child(__x)) 
+        __x->__parent_->__left_ = __y; 
+    else 
+        __x->__parent_unsafe()->__right_ = __y; 
+    __y->__left_ = __x; 
+    __x->__set_parent(__y); 
+} 
+ 
+// Effects:  Makes __x->__left_ the subtree root with __x as its right child 
+//           while preserving in-order order. 
+// Precondition:  __x->__left_ != nullptr 
+template <class _NodePtr> 
+void 
+__tree_right_rotate(_NodePtr __x) _NOEXCEPT 
+{ 
+    _NodePtr __y = __x->__left_; 
+    __x->__left_ = __y->__right_; 
+    if (__x->__left_ != nullptr) 
+        __x->__left_->__set_parent(__x); 
+    __y->__parent_ = __x->__parent_; 
+    if (_VSTD::__tree_is_left_child(__x)) 
+        __x->__parent_->__left_ = __y; 
+    else 
+        __x->__parent_unsafe()->__right_ = __y; 
+    __y->__right_ = __x; 
+    __x->__set_parent(__y); 
+} 
+ 
+// Effects:  Rebalances __root after attaching __x to a leaf. 
+// Precondition:  __root != nulptr && __x != nullptr. 
+//                __x has no children. 
+//                __x == __root or == a direct or indirect child of __root. 
+//                If __x were to be unlinked from __root (setting __root to 
+//                  nullptr if __root == __x), __tree_invariant(__root) == true. 
+// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_ 
+//                may be different than the value passed in as __root. 
+template <class _NodePtr> 
+void 
+__tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT 
+{ 
+    __x->__is_black_ = __x == __root; 
+    while (__x != __root && !__x->__parent_unsafe()->__is_black_) 
+    { 
+        // __x->__parent_ != __root because __x->__parent_->__is_black == false 
+        if (_VSTD::__tree_is_left_child(__x->__parent_unsafe())) 
+        { 
+            _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_; 
+            if (__y != nullptr && !__y->__is_black_) 
+            { 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = true; 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = __x == __root; 
+                __y->__is_black_ = true; 
+            } 
+            else 
+            { 
+                if (!_VSTD::__tree_is_left_child(__x)) 
+                { 
+                    __x = __x->__parent_unsafe(); 
+                    _VSTD::__tree_left_rotate(__x); 
+                } 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = true; 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = false; 
+                _VSTD::__tree_right_rotate(__x); 
+                break; 
+            } 
+        } 
+        else 
+        { 
+            _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_; 
+            if (__y != nullptr && !__y->__is_black_) 
+            { 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = true; 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = __x == __root; 
+                __y->__is_black_ = true; 
+            } 
+            else 
+            { 
+                if (_VSTD::__tree_is_left_child(__x)) 
+                { 
+                    __x = __x->__parent_unsafe(); 
+                    _VSTD::__tree_right_rotate(__x); 
+                } 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = true; 
+                __x = __x->__parent_unsafe(); 
+                __x->__is_black_ = false; 
+                _VSTD::__tree_left_rotate(__x); 
+                break; 
+            } 
+        } 
+    } 
+} 
+ 
+// Precondition:  __root != nullptr && __z != nullptr. 
+//                __tree_invariant(__root) == true. 
+//                __z == __root or == a direct or indirect child of __root. 
+// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed. 
+// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_ 
+//                nor any of its children refer to __z.  end_node->__left_ 
+//                may be different than the value passed in as __root. 
+template <class _NodePtr> 
+void 
+__tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT 
+{ 
+    // __z will be removed from the tree.  Client still needs to destruct/deallocate it 
+    // __y is either __z, or if __z has two children, __tree_next(__z). 
+    // __y will have at most one child. 
+    // __y will be the initial hole in the tree (make the hole at a leaf) 
+    _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ? 
+                    __z : _VSTD::__tree_next(__z); 
+    // __x is __y's possibly null single child 
+    _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_; 
+    // __w is __x's possibly null uncle (will become __x's sibling) 
+    _NodePtr __w = nullptr; 
+    // link __x to __y's parent, and find __w 
+    if (__x != nullptr) 
+        __x->__parent_ = __y->__parent_; 
+    if (_VSTD::__tree_is_left_child(__y)) 
+    { 
+        __y->__parent_->__left_ = __x; 
+        if (__y != __root) 
+            __w = __y->__parent_unsafe()->__right_; 
+        else 
+            __root = __x;  // __w == nullptr 
+    } 
+    else 
+    { 
+        __y->__parent_unsafe()->__right_ = __x; 
+        // __y can't be root if it is a right child 
+        __w = __y->__parent_->__left_; 
+    } 
+    bool __removed_black = __y->__is_black_; 
+    // If we didn't remove __z, do so now by splicing in __y for __z, 
+    //    but copy __z's color.  This does not impact __x or __w. 
+    if (__y != __z) 
+    { 
+        // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr 
+        __y->__parent_ = __z->__parent_; 
+        if (_VSTD::__tree_is_left_child(__z)) 
+            __y->__parent_->__left_ = __y; 
+        else 
+            __y->__parent_unsafe()->__right_ = __y; 
+        __y->__left_ = __z->__left_; 
+        __y->__left_->__set_parent(__y); 
+        __y->__right_ = __z->__right_; 
+        if (__y->__right_ != nullptr) 
+            __y->__right_->__set_parent(__y); 
+        __y->__is_black_ = __z->__is_black_; 
+        if (__root == __z) 
+            __root = __y; 
+    } 
+    // There is no need to rebalance if we removed a red, or if we removed 
+    //     the last node. 
+    if (__removed_black && __root != nullptr) 
+    { 
+        // Rebalance: 
+        // __x has an implicit black color (transferred from the removed __y) 
+        //    associated with it, no matter what its color is. 
+        // If __x is __root (in which case it can't be null), it is supposed 
+        //    to be black anyway, and if it is doubly black, then the double 
+        //    can just be ignored. 
+        // If __x is red (in which case it can't be null), then it can absorb 
+        //    the implicit black just by setting its color to black. 
+        // Since __y was black and only had one child (which __x points to), __x 
+        //   is either red with no children, else null, otherwise __y would have 
+        //   different black heights under left and right pointers. 
+        // if (__x == __root || __x != nullptr && !__x->__is_black_) 
+        if (__x != nullptr) 
+            __x->__is_black_ = true; 
+        else 
+        { 
+            //  Else __x isn't root, and is "doubly black", even though it may 
+            //     be null.  __w can not be null here, else the parent would 
+            //     see a black height >= 2 on the __x side and a black height 
+            //     of 1 on the __w side (__w must be a non-null black or a red 
+            //     with a non-null black child). 
+            while (true) 
+            { 
+                if (!_VSTD::__tree_is_left_child(__w))  // if x is left child 
+                { 
+                    if (!__w->__is_black_) 
+                    { 
+                        __w->__is_black_ = true; 
+                        __w->__parent_unsafe()->__is_black_ = false; 
+                        _VSTD::__tree_left_rotate(__w->__parent_unsafe()); 
+                        // __x is still valid 
+                        // reset __root only if necessary 
+                        if (__root == __w->__left_) 
+                            __root = __w; 
+                        // reset sibling, and it still can't be null 
+                        __w = __w->__left_->__right_; 
+                    } 
+                    // __w->__is_black_ is now true, __w may have null children 
+                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) && 
+                        (__w->__right_ == nullptr || __w->__right_->__is_black_)) 
+                    { 
+                        __w->__is_black_ = false; 
+                        __x = __w->__parent_unsafe(); 
+                        // __x can no longer be null 
+                        if (__x == __root || !__x->__is_black_) 
+                        { 
+                            __x->__is_black_ = true; 
+                            break; 
+                        } 
+                        // reset sibling, and it still can't be null 
+                        __w = _VSTD::__tree_is_left_child(__x) ? 
+                                    __x->__parent_unsafe()->__right_ : 
+                                    __x->__parent_->__left_; 
+                        // continue; 
+                    } 
+                    else  // __w has a red child 
+                    { 
+                        if (__w->__right_ == nullptr || __w->__right_->__is_black_) 
+                        { 
+                            // __w left child is non-null and red 
+                            __w->__left_->__is_black_ = true; 
+                            __w->__is_black_ = false; 
+                            _VSTD::__tree_right_rotate(__w); 
+                            // __w is known not to be root, so root hasn't changed 
+                            // reset sibling, and it still can't be null 
+                            __w = __w->__parent_unsafe(); 
+                        } 
+                        // __w has a right red child, left child may be null 
+                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_; 
+                        __w->__parent_unsafe()->__is_black_ = true; 
+                        __w->__right_->__is_black_ = true; 
+                        _VSTD::__tree_left_rotate(__w->__parent_unsafe()); 
+                        break; 
+                    } 
+                } 
+                else 
+                { 
+                    if (!__w->__is_black_) 
+                    { 
+                        __w->__is_black_ = true; 
+                        __w->__parent_unsafe()->__is_black_ = false; 
+                        _VSTD::__tree_right_rotate(__w->__parent_unsafe()); 
+                        // __x is still valid 
+                        // reset __root only if necessary 
+                        if (__root == __w->__right_) 
+                            __root = __w; 
+                        // reset sibling, and it still can't be null 
+                        __w = __w->__right_->__left_; 
+                    } 
+                    // __w->__is_black_ is now true, __w may have null children 
+                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) && 
+                        (__w->__right_ == nullptr || __w->__right_->__is_black_)) 
+                    { 
+                        __w->__is_black_ = false; 
+                        __x = __w->__parent_unsafe(); 
+                        // __x can no longer be null 
+                        if (!__x->__is_black_ || __x == __root) 
+                        { 
+                            __x->__is_black_ = true; 
+                            break; 
+                        } 
+                        // reset sibling, and it still can't be null 
+                        __w = _VSTD::__tree_is_left_child(__x) ? 
+                                    __x->__parent_unsafe()->__right_ : 
+                                    __x->__parent_->__left_; 
+                        // continue; 
+                    } 
+                    else  // __w has a red child 
+                    { 
+                        if (__w->__left_ == nullptr || __w->__left_->__is_black_) 
+                        { 
+                            // __w right child is non-null and red 
+                            __w->__right_->__is_black_ = true; 
+                            __w->__is_black_ = false; 
+                            _VSTD::__tree_left_rotate(__w); 
+                            // __w is known not to be root, so root hasn't changed 
+                            // reset sibling, and it still can't be null 
+                            __w = __w->__parent_unsafe(); 
+                        } 
+                        // __w has a left red child, right child may be null 
+                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_; 
+                        __w->__parent_unsafe()->__is_black_ = true; 
+                        __w->__left_->__is_black_ = true; 
+                        _VSTD::__tree_right_rotate(__w->__parent_unsafe()); 
+                        break; 
+                    } 
+                } 
+            } 
+        } 
+    } 
+} 
+ 
+// node traits 
+ 
+ 
+template <class _Tp> 
+struct __is_tree_value_type_imp : false_type {}; 
+ 
+template <class _Key, class _Value> 
 struct __is_tree_value_type_imp<__value_type<_Key, _Value> > : true_type {};
-
-template <class ..._Args>
-struct __is_tree_value_type : false_type {};
-
-template <class _One>
-struct __is_tree_value_type<_One> : __is_tree_value_type_imp<typename __uncvref<_One>::type> {};
-
-template <class _Tp>
-struct __tree_key_value_types {
-  typedef _Tp key_type;
-  typedef _Tp __node_value_type;
-  typedef _Tp __container_value_type;
-  static const bool __is_map = false;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static key_type const& __get_key(_Tp const& __v) {
-    return __v;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type const& __get_value(__node_value_type const& __v) {
-    return __v;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type* __get_ptr(__node_value_type& __n) {
-    return _VSTD::addressof(__n);
-  }
-  _LIBCPP_INLINE_VISIBILITY
+ 
+template <class ..._Args> 
+struct __is_tree_value_type : false_type {}; 
+ 
+template <class _One> 
+struct __is_tree_value_type<_One> : __is_tree_value_type_imp<typename __uncvref<_One>::type> {}; 
+ 
+template <class _Tp> 
+struct __tree_key_value_types { 
+  typedef _Tp key_type; 
+  typedef _Tp __node_value_type; 
+  typedef _Tp __container_value_type; 
+  static const bool __is_map = false; 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+  static key_type const& __get_key(_Tp const& __v) { 
+    return __v; 
+  } 
+  _LIBCPP_INLINE_VISIBILITY 
+  static __container_value_type const& __get_value(__node_value_type const& __v) { 
+    return __v; 
+  } 
+  _LIBCPP_INLINE_VISIBILITY 
+  static __container_value_type* __get_ptr(__node_value_type& __n) { 
+    return _VSTD::addressof(__n); 
+  } 
+  _LIBCPP_INLINE_VISIBILITY 
   static __container_value_type&& __move(__node_value_type& __v) {
-    return _VSTD::move(__v);
-  }
-};
-
-template <class _Key, class _Tp>
-struct __tree_key_value_types<__value_type<_Key, _Tp> > {
-  typedef _Key                                         key_type;
-  typedef _Tp                                          mapped_type;
-  typedef __value_type<_Key, _Tp>                      __node_value_type;
-  typedef pair<const _Key, _Tp>                        __container_value_type;
-  typedef __container_value_type                       __map_value_type;
-  static const bool __is_map = true;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static key_type const&
-  __get_key(__node_value_type const& __t) {
-    return __t.__get_value().first;
-  }
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
-      key_type const&>::type
-  __get_key(_Up& __t) {
-    return __t.first;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type const&
-  __get_value(__node_value_type const& __t) {
-    return __t.__get_value();
-  }
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
-      __container_value_type const&>::type
-  __get_value(_Up& __t) {
-    return __t;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type* __get_ptr(__node_value_type& __n) {
-    return _VSTD::addressof(__n.__get_value());
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
-    return __v.__move();
-  }
-};
-
-template <class _VoidPtr>
-struct __tree_node_base_types {
-  typedef _VoidPtr                                               __void_pointer;
-
-  typedef __tree_node_base<__void_pointer>                      __node_base_type;
-  typedef typename __rebind_pointer<_VoidPtr, __node_base_type>::type
-                                                             __node_base_pointer;
-
-  typedef __tree_end_node<__node_base_pointer>                  __end_node_type;
-  typedef typename __rebind_pointer<_VoidPtr, __end_node_type>::type
-                                                             __end_node_pointer;
-#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB)
-  typedef __end_node_pointer __parent_pointer;
-#else
-  typedef typename conditional<
-      is_pointer<__end_node_pointer>::value,
-        __end_node_pointer,
-        __node_base_pointer>::type __parent_pointer;
-#endif
-
-private:
-  static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
-                  "_VoidPtr does not point to unqualified void type");
-};
-
-template <class _Tp, class _AllocPtr, class _KVTypes = __tree_key_value_types<_Tp>,
-         bool = _KVTypes::__is_map>
-struct __tree_map_pointer_types {};
-
-template <class _Tp, class _AllocPtr, class _KVTypes>
-struct __tree_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
-  typedef typename _KVTypes::__map_value_type   _Mv;
-  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
-                                                       __map_value_type_pointer;
-  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
-                                                 __const_map_value_type_pointer;
-};
-
-template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
-struct __tree_node_types;
-
-template <class _NodePtr, class _Tp, class _VoidPtr>
-struct __tree_node_types<_NodePtr, __tree_node<_Tp, _VoidPtr> >
-    : public __tree_node_base_types<_VoidPtr>,
-             __tree_key_value_types<_Tp>,
-             __tree_map_pointer_types<_Tp, _VoidPtr>
-{
-  typedef __tree_node_base_types<_VoidPtr> __base;
-  typedef __tree_key_value_types<_Tp>      __key_base;
-  typedef __tree_map_pointer_types<_Tp, _VoidPtr> __map_pointer_base;
-public:
-
-  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
-  typedef _NodePtr                                              __node_pointer;
-
-  typedef _Tp                                                 __node_value_type;
-  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
-                                                      __node_value_type_pointer;
-  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
-                                                __const_node_value_type_pointer;
-#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB)
-  typedef typename __base::__end_node_pointer __iter_pointer;
-#else
-  typedef typename conditional<
-      is_pointer<__node_pointer>::value,
-        typename __base::__end_node_pointer,
-        __node_pointer>::type __iter_pointer;
-#endif
-private:
-    static_assert(!is_const<__node_type>::value,
-                "_NodePtr should never be a pointer to const");
-    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
-                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
-};
-
-template <class _ValueTp, class _VoidPtr>
-struct __make_tree_node_types {
-  typedef typename __rebind_pointer<_VoidPtr, __tree_node<_ValueTp, _VoidPtr> >::type
-                                                                        _NodePtr;
-  typedef __tree_node_types<_NodePtr> type;
-};
-
-// node
-
-template <class _Pointer>
-class __tree_end_node
-{
-public:
-    typedef _Pointer pointer;
-    pointer __left_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_end_node() _NOEXCEPT : __left_() {}
-};
-
-template <class _VoidPtr>
-class _LIBCPP_STANDALONE_DEBUG __tree_node_base
-    : public __tree_node_base_types<_VoidPtr>::__end_node_type
-{
-    typedef __tree_node_base_types<_VoidPtr> _NodeBaseTypes;
-
-public:
-    typedef typename _NodeBaseTypes::__node_base_pointer pointer;
-    typedef typename _NodeBaseTypes::__parent_pointer __parent_pointer;
-
-    pointer          __right_;
-    __parent_pointer __parent_;
-    bool __is_black_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer __parent_unsafe() const { return static_cast<pointer>(__parent_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_parent(pointer __p) {
-        __parent_ = static_cast<__parent_pointer>(__p);
-    }
-
-private:
-  ~__tree_node_base() = delete;
-  __tree_node_base(__tree_node_base const&) = delete;
-  __tree_node_base& operator=(__tree_node_base const&) = delete;
-};
-
-template <class _Tp, class _VoidPtr>
-class _LIBCPP_STANDALONE_DEBUG __tree_node
-    : public __tree_node_base<_VoidPtr>
-{
-public:
-    typedef _Tp __node_value_type;
-
-    __node_value_type __value_;
-
-private:
-  ~__tree_node() = delete;
-  __tree_node(__tree_node const&) = delete;
-  __tree_node& operator=(__tree_node const&) = delete;
-};
-
-
-template <class _Allocator>
-class __tree_node_destructor
-{
-    typedef _Allocator                                      allocator_type;
-    typedef allocator_traits<allocator_type>                __alloc_traits;
-
-public:
-    typedef typename __alloc_traits::pointer                pointer;
-private:
-    typedef __tree_node_types<pointer> _NodeTypes;
-    allocator_type& __na_;
-
-
-public:
-    bool __value_constructed;
-
-
-    __tree_node_destructor(const __tree_node_destructor &) = default;
-    __tree_node_destructor& operator=(const __tree_node_destructor&) = delete;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT
-        : __na_(__na),
-          __value_constructed(__val)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-    {
-        if (__value_constructed)
-            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
-
-    template <class> friend class __map_node_destructor;
-};
-
+    return _VSTD::move(__v); 
+  } 
+}; 
+ 
+template <class _Key, class _Tp> 
+struct __tree_key_value_types<__value_type<_Key, _Tp> > { 
+  typedef _Key                                         key_type; 
+  typedef _Tp                                          mapped_type; 
+  typedef __value_type<_Key, _Tp>                      __node_value_type; 
+  typedef pair<const _Key, _Tp>                        __container_value_type; 
+  typedef __container_value_type                       __map_value_type; 
+  static const bool __is_map = true; 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+  static key_type const& 
+  __get_key(__node_value_type const& __t) { 
+    return __t.__get_value().first; 
+  } 
+ 
+  template <class _Up> 
+  _LIBCPP_INLINE_VISIBILITY 
+  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value, 
+      key_type const&>::type 
+  __get_key(_Up& __t) { 
+    return __t.first; 
+  } 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+  static __container_value_type const& 
+  __get_value(__node_value_type const& __t) { 
+    return __t.__get_value(); 
+  } 
+ 
+  template <class _Up> 
+  _LIBCPP_INLINE_VISIBILITY 
+  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value, 
+      __container_value_type const&>::type 
+  __get_value(_Up& __t) { 
+    return __t; 
+  } 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+  static __container_value_type* __get_ptr(__node_value_type& __n) { 
+    return _VSTD::addressof(__n.__get_value()); 
+  } 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) { 
+    return __v.__move(); 
+  } 
+}; 
+ 
+template <class _VoidPtr> 
+struct __tree_node_base_types { 
+  typedef _VoidPtr                                               __void_pointer; 
+ 
+  typedef __tree_node_base<__void_pointer>                      __node_base_type; 
+  typedef typename __rebind_pointer<_VoidPtr, __node_base_type>::type 
+                                                             __node_base_pointer; 
+ 
+  typedef __tree_end_node<__node_base_pointer>                  __end_node_type; 
+  typedef typename __rebind_pointer<_VoidPtr, __end_node_type>::type 
+                                                             __end_node_pointer; 
+#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB) 
+  typedef __end_node_pointer __parent_pointer; 
+#else 
+  typedef typename conditional< 
+      is_pointer<__end_node_pointer>::value, 
+        __end_node_pointer, 
+        __node_base_pointer>::type __parent_pointer; 
+#endif 
+ 
+private: 
+  static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value), 
+                  "_VoidPtr does not point to unqualified void type"); 
+}; 
+ 
+template <class _Tp, class _AllocPtr, class _KVTypes = __tree_key_value_types<_Tp>, 
+         bool = _KVTypes::__is_map> 
+struct __tree_map_pointer_types {}; 
+ 
+template <class _Tp, class _AllocPtr, class _KVTypes> 
+struct __tree_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> { 
+  typedef typename _KVTypes::__map_value_type   _Mv; 
+  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type 
+                                                       __map_value_type_pointer; 
+  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type 
+                                                 __const_map_value_type_pointer; 
+}; 
+ 
+template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type> 
+struct __tree_node_types; 
+ 
+template <class _NodePtr, class _Tp, class _VoidPtr> 
+struct __tree_node_types<_NodePtr, __tree_node<_Tp, _VoidPtr> > 
+    : public __tree_node_base_types<_VoidPtr>, 
+             __tree_key_value_types<_Tp>, 
+             __tree_map_pointer_types<_Tp, _VoidPtr> 
+{ 
+  typedef __tree_node_base_types<_VoidPtr> __base; 
+  typedef __tree_key_value_types<_Tp>      __key_base; 
+  typedef __tree_map_pointer_types<_Tp, _VoidPtr> __map_pointer_base; 
+public: 
+ 
+  typedef typename pointer_traits<_NodePtr>::element_type       __node_type; 
+  typedef _NodePtr                                              __node_pointer; 
+ 
+  typedef _Tp                                                 __node_value_type; 
+  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type 
+                                                      __node_value_type_pointer; 
+  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type 
+                                                __const_node_value_type_pointer; 
+#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB) 
+  typedef typename __base::__end_node_pointer __iter_pointer; 
+#else 
+  typedef typename conditional< 
+      is_pointer<__node_pointer>::value, 
+        typename __base::__end_node_pointer, 
+        __node_pointer>::type __iter_pointer; 
+#endif 
+private: 
+    static_assert(!is_const<__node_type>::value, 
+                "_NodePtr should never be a pointer to const"); 
+    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type, 
+                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr."); 
+}; 
+ 
+template <class _ValueTp, class _VoidPtr> 
+struct __make_tree_node_types { 
+  typedef typename __rebind_pointer<_VoidPtr, __tree_node<_ValueTp, _VoidPtr> >::type 
+                                                                        _NodePtr; 
+  typedef __tree_node_types<_NodePtr> type; 
+}; 
+ 
+// node 
+ 
+template <class _Pointer> 
+class __tree_end_node 
+{ 
+public: 
+    typedef _Pointer pointer; 
+    pointer __left_; 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_end_node() _NOEXCEPT : __left_() {} 
+}; 
+ 
+template <class _VoidPtr> 
+class _LIBCPP_STANDALONE_DEBUG __tree_node_base 
+    : public __tree_node_base_types<_VoidPtr>::__end_node_type 
+{ 
+    typedef __tree_node_base_types<_VoidPtr> _NodeBaseTypes; 
+ 
+public: 
+    typedef typename _NodeBaseTypes::__node_base_pointer pointer; 
+    typedef typename _NodeBaseTypes::__parent_pointer __parent_pointer; 
+ 
+    pointer          __right_; 
+    __parent_pointer __parent_; 
+    bool __is_black_; 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    pointer __parent_unsafe() const { return static_cast<pointer>(__parent_);} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __set_parent(pointer __p) { 
+        __parent_ = static_cast<__parent_pointer>(__p); 
+    } 
+ 
+private: 
+  ~__tree_node_base() = delete; 
+  __tree_node_base(__tree_node_base const&) = delete; 
+  __tree_node_base& operator=(__tree_node_base const&) = delete; 
+}; 
+ 
+template <class _Tp, class _VoidPtr> 
+class _LIBCPP_STANDALONE_DEBUG __tree_node 
+    : public __tree_node_base<_VoidPtr> 
+{ 
+public: 
+    typedef _Tp __node_value_type; 
+ 
+    __node_value_type __value_; 
+ 
+private: 
+  ~__tree_node() = delete; 
+  __tree_node(__tree_node const&) = delete; 
+  __tree_node& operator=(__tree_node const&) = delete; 
+}; 
+ 
+ 
+template <class _Allocator> 
+class __tree_node_destructor 
+{ 
+    typedef _Allocator                                      allocator_type; 
+    typedef allocator_traits<allocator_type>                __alloc_traits; 
+ 
+public: 
+    typedef typename __alloc_traits::pointer                pointer; 
+private: 
+    typedef __tree_node_types<pointer> _NodeTypes; 
+    allocator_type& __na_; 
+ 
+ 
+public: 
+    bool __value_constructed; 
+ 
+ 
+    __tree_node_destructor(const __tree_node_destructor &) = default; 
+    __tree_node_destructor& operator=(const __tree_node_destructor&) = delete; 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT 
+        : __na_(__na), 
+          __value_constructed(__val) 
+        {} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    void operator()(pointer __p) _NOEXCEPT 
+    { 
+        if (__value_constructed) 
+            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_)); 
+        if (__p) 
+            __alloc_traits::deallocate(__na_, __p, 1); 
+    } 
+ 
+    template <class> friend class __map_node_destructor; 
+}; 
+ 
 #if _LIBCPP_STD_VER > 14
 template <class _NodeType, class _Alloc>
 struct __generic_container_node_destructor;
@@ -807,516 +807,516 @@ struct __generic_container_node_destructor<__tree_node<_Tp, _VoidPtr>, _Alloc>
     using __tree_node_destructor<_Alloc>::__tree_node_destructor;
 };
 #endif
-
-template <class _Tp, class _NodePtr, class _DiffType>
-class _LIBCPP_TEMPLATE_VIS __tree_iterator
-{
-    typedef __tree_node_types<_NodePtr>                     _NodeTypes;
-    typedef _NodePtr                                        __node_pointer;
-    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer;
-    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer;
-    typedef typename _NodeTypes::__iter_pointer             __iter_pointer;
-    typedef pointer_traits<__node_pointer> __pointer_traits;
-
-    __iter_pointer __ptr_;
-
-public:
-    typedef bidirectional_iterator_tag                     iterator_category;
-    typedef _Tp                                            value_type;
-    typedef _DiffType                                      difference_type;
-    typedef value_type&                                    reference;
-    typedef typename _NodeTypes::__node_value_type_pointer pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __tree_iterator() _NOEXCEPT
-#if _LIBCPP_STD_VER > 11
-    : __ptr_(nullptr)
-#endif
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const
-        {return __get_np()->__value_;}
-    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
-        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator& operator++() {
-      __ptr_ = static_cast<__iter_pointer>(
-          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
-      return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator operator++(int)
-        {__tree_iterator __t(*this); ++(*this); return __t;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator& operator--() {
-      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>(
-          static_cast<__end_node_pointer>(__ptr_)));
-      return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator operator--(int)
-        {__tree_iterator __t(*this); --(*this); return __t;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const __tree_iterator& __x, const __tree_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_iterator(__end_node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); }
-    template <class, class, class> friend class __tree;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_iterator;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset;
-};
-
-template <class _Tp, class _NodePtr, class _DiffType>
-class _LIBCPP_TEMPLATE_VIS __tree_const_iterator
-{
-    typedef __tree_node_types<_NodePtr>                     _NodeTypes;
-    typedef typename _NodeTypes::__node_pointer             __node_pointer;
-    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer;
-    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer;
-    typedef typename _NodeTypes::__iter_pointer             __iter_pointer;
-    typedef pointer_traits<__node_pointer> __pointer_traits;
-
-    __iter_pointer __ptr_;
-
-public:
-    typedef bidirectional_iterator_tag                           iterator_category;
-    typedef _Tp                                                  value_type;
-    typedef _DiffType                                            difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __tree_const_iterator() _NOEXCEPT
-#if _LIBCPP_STD_VER > 11
-    : __ptr_(nullptr)
-#endif
-    {}
-
-private:
-    typedef __tree_iterator<value_type, __node_pointer, difference_type>
-                                                           __non_const_iterator;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT
-        : __ptr_(__p.__ptr_) {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const
-        {return __get_np()->__value_;}
-    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
-        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator& operator++() {
-      __ptr_ = static_cast<__iter_pointer>(
-          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
-      return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator operator++(int)
-        {__tree_const_iterator __t(*this); ++(*this); return __t;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator& operator--() {
-      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>(
-          static_cast<__end_node_pointer>(__ptr_)));
-      return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator operator--(int)
-        {__tree_const_iterator __t(*this); --(*this); return __t;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT
-        : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_const_iterator(__end_node_pointer __p) _NOEXCEPT
-        : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); }
-
-    template <class, class, class> friend class __tree;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
-
-};
-
+ 
+template <class _Tp, class _NodePtr, class _DiffType> 
+class _LIBCPP_TEMPLATE_VIS __tree_iterator 
+{ 
+    typedef __tree_node_types<_NodePtr>                     _NodeTypes; 
+    typedef _NodePtr                                        __node_pointer; 
+    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer; 
+    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer; 
+    typedef typename _NodeTypes::__iter_pointer             __iter_pointer; 
+    typedef pointer_traits<__node_pointer> __pointer_traits; 
+ 
+    __iter_pointer __ptr_; 
+ 
+public: 
+    typedef bidirectional_iterator_tag                     iterator_category; 
+    typedef _Tp                                            value_type; 
+    typedef _DiffType                                      difference_type; 
+    typedef value_type&                                    reference; 
+    typedef typename _NodeTypes::__node_value_type_pointer pointer; 
+ 
+    _LIBCPP_INLINE_VISIBILITY __tree_iterator() _NOEXCEPT 
+#if _LIBCPP_STD_VER > 11 
+    : __ptr_(nullptr) 
+#endif 
+    {} 
+ 
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const 
+        {return __get_np()->__value_;} 
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const 
+        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_iterator& operator++() { 
+      __ptr_ = static_cast<__iter_pointer>( 
+          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_))); 
+      return *this; 
+    } 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_iterator operator++(int) 
+        {__tree_iterator __t(*this); ++(*this); return __t;} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_iterator& operator--() { 
+      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>( 
+          static_cast<__end_node_pointer>(__ptr_))); 
+      return *this; 
+    } 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_iterator operator--(int) 
+        {__tree_iterator __t(*this); --(*this); return __t;} 
+ 
+    friend _LIBCPP_INLINE_VISIBILITY 
+        bool operator==(const __tree_iterator& __x, const __tree_iterator& __y) 
+        {return __x.__ptr_ == __y.__ptr_;} 
+    friend _LIBCPP_INLINE_VISIBILITY 
+        bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y) 
+        {return !(__x == __y);} 
+ 
+private: 
+    _LIBCPP_INLINE_VISIBILITY 
+    explicit __tree_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {} 
+    _LIBCPP_INLINE_VISIBILITY 
+    explicit __tree_iterator(__end_node_pointer __p) _NOEXCEPT : __ptr_(__p) {} 
+    _LIBCPP_INLINE_VISIBILITY 
+    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); } 
+    template <class, class, class> friend class __tree; 
+    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS __tree_const_iterator; 
+    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_iterator; 
+    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map; 
+    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap; 
+    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set; 
+    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset; 
+}; 
+ 
+template <class _Tp, class _NodePtr, class _DiffType> 
+class _LIBCPP_TEMPLATE_VIS __tree_const_iterator 
+{ 
+    typedef __tree_node_types<_NodePtr>                     _NodeTypes; 
+    typedef typename _NodeTypes::__node_pointer             __node_pointer; 
+    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer; 
+    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer; 
+    typedef typename _NodeTypes::__iter_pointer             __iter_pointer; 
+    typedef pointer_traits<__node_pointer> __pointer_traits; 
+ 
+    __iter_pointer __ptr_; 
+ 
+public: 
+    typedef bidirectional_iterator_tag                           iterator_category; 
+    typedef _Tp                                                  value_type; 
+    typedef _DiffType                                            difference_type; 
+    typedef const value_type&                                    reference; 
+    typedef typename _NodeTypes::__const_node_value_type_pointer pointer; 
+ 
+    _LIBCPP_INLINE_VISIBILITY __tree_const_iterator() _NOEXCEPT 
+#if _LIBCPP_STD_VER > 11 
+    : __ptr_(nullptr) 
+#endif 
+    {} 
+ 
+private: 
+    typedef __tree_iterator<value_type, __node_pointer, difference_type> 
+                                                           __non_const_iterator; 
+public: 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT 
+        : __ptr_(__p.__ptr_) {} 
+ 
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const 
+        {return __get_np()->__value_;} 
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const 
+        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_const_iterator& operator++() { 
+      __ptr_ = static_cast<__iter_pointer>( 
+          _VSTD::__tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_))); 
+      return *this; 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_const_iterator operator++(int) 
+        {__tree_const_iterator __t(*this); ++(*this); return __t;} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_const_iterator& operator--() { 
+      __ptr_ = static_cast<__iter_pointer>(_VSTD::__tree_prev_iter<__node_base_pointer>( 
+          static_cast<__end_node_pointer>(__ptr_))); 
+      return *this; 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __tree_const_iterator operator--(int) 
+        {__tree_const_iterator __t(*this); --(*this); return __t;} 
+ 
+    friend _LIBCPP_INLINE_VISIBILITY 
+        bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y) 
+        {return __x.__ptr_ == __y.__ptr_;} 
+    friend _LIBCPP_INLINE_VISIBILITY 
+        bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y) 
+        {return !(__x == __y);} 
+ 
+private: 
+    _LIBCPP_INLINE_VISIBILITY 
+    explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT 
+        : __ptr_(__p) {} 
+    _LIBCPP_INLINE_VISIBILITY 
+    explicit __tree_const_iterator(__end_node_pointer __p) _NOEXCEPT 
+        : __ptr_(__p) {} 
+    _LIBCPP_INLINE_VISIBILITY 
+    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); } 
+ 
+    template <class, class, class> friend class __tree; 
+    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map; 
+    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap; 
+    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set; 
+    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset; 
+    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_const_iterator; 
+ 
+}; 
+ 
 template<class _Tp, class _Compare>
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Compare const&, _Tp const&, _Tp const&>::value,
-        "the specified comparator type does not provide a viable const call operator")
+#ifndef _LIBCPP_CXX03_LANG 
+    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Compare const&, _Tp const&, _Tp const&>::value, 
+        "the specified comparator type does not provide a viable const call operator") 
 #endif
 int __diagnose_non_const_comparator();
-
-template <class _Tp, class _Compare, class _Allocator>
-class __tree
-{
-public:
-    typedef _Tp                                      value_type;
-    typedef _Compare                                 value_compare;
-    typedef _Allocator                               allocator_type;
-
-private:
-    typedef allocator_traits<allocator_type>         __alloc_traits;
-    typedef typename __make_tree_node_types<value_type,
-        typename __alloc_traits::void_pointer>::type
-                                                    _NodeTypes;
-    typedef typename _NodeTypes::key_type           key_type;
-public:
-    typedef typename _NodeTypes::__node_value_type      __node_value_type;
-    typedef typename _NodeTypes::__container_value_type __container_value_type;
-
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef typename __alloc_traits::size_type       size_type;
-    typedef typename __alloc_traits::difference_type difference_type;
-
-public:
-    typedef typename _NodeTypes::__void_pointer        __void_pointer;
-
-    typedef typename _NodeTypes::__node_type           __node;
-    typedef typename _NodeTypes::__node_pointer        __node_pointer;
-
-    typedef typename _NodeTypes::__node_base_type      __node_base;
-    typedef typename _NodeTypes::__node_base_pointer   __node_base_pointer;
-
-    typedef typename _NodeTypes::__end_node_type       __end_node_t;
-    typedef typename _NodeTypes::__end_node_pointer    __end_node_ptr;
-
-    typedef typename _NodeTypes::__parent_pointer      __parent_pointer;
-    typedef typename _NodeTypes::__iter_pointer        __iter_pointer;
-
-    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
-    typedef allocator_traits<__node_allocator>         __node_traits;
-
-private:
-    // check for sane allocator pointer rebinding semantics. Rebinding the
-    // allocator for a new pointer type should be exactly the same as rebinding
-    // the pointer using 'pointer_traits'.
-    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
-                  "Allocator does not rebind pointers in a sane manner.");
-    typedef typename __rebind_alloc_helper<__node_traits, __node_base>::type
-        __node_base_allocator;
-    typedef allocator_traits<__node_base_allocator> __node_base_traits;
-    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
-                 "Allocator does not rebind pointers in a sane manner.");
-
-private:
-    __iter_pointer                                     __begin_node_;
-    __compressed_pair<__end_node_t, __node_allocator>  __pair1_;
-    __compressed_pair<size_type, value_compare>        __pair3_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __iter_pointer __end_node() _NOEXCEPT
-    {
-        return static_cast<__iter_pointer>(
-                pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first())
-        );
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __iter_pointer __end_node() const _NOEXCEPT
-    {
-        return static_cast<__iter_pointer>(
-            pointer_traits<__end_node_ptr>::pointer_to(
-                const_cast<__end_node_t&>(__pair1_.first())
-            )
-        );
-    }
-    _LIBCPP_INLINE_VISIBILITY
-          __node_allocator& __node_alloc() _NOEXCEPT {return __pair1_.second();}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    const __node_allocator& __node_alloc() const _NOEXCEPT
-        {return __pair1_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-          __iter_pointer& __begin_node() _NOEXCEPT {return __begin_node_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const __iter_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;}
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type __alloc() const _NOEXCEPT
-        {return allocator_type(__node_alloc());}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-          size_type& size() _NOEXCEPT {return __pair3_.first();}
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    const size_type& size() const _NOEXCEPT {return __pair3_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-          value_compare& value_comp() _NOEXCEPT {return __pair3_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_compare& value_comp() const _NOEXCEPT
-        {return __pair3_.second();}
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __root() const _NOEXCEPT
-        {return static_cast<__node_pointer>(__end_node()->__left_);}
-
-    __node_base_pointer* __root_ptr() const _NOEXCEPT {
-        return _VSTD::addressof(__end_node()->__left_);
-    }
-
-    typedef __tree_iterator<value_type, __node_pointer, difference_type>             iterator;
-    typedef __tree_const_iterator<value_type, __node_pointer, difference_type> const_iterator;
-
-    explicit __tree(const value_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<__node_allocator>::value &&
-            is_nothrow_copy_constructible<value_compare>::value);
-    explicit __tree(const allocator_type& __a);
-    __tree(const value_compare& __comp, const allocator_type& __a);
-    __tree(const __tree& __t);
-    __tree& operator=(const __tree& __t);
-    template <class _ForwardIterator>
-        void __assign_unique(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _InputIterator>
-        void __assign_multi(_InputIterator __first, _InputIterator __last);
-    __tree(__tree&& __t)
-        _NOEXCEPT_(
-            is_nothrow_move_constructible<__node_allocator>::value &&
-            is_nothrow_move_constructible<value_compare>::value);
-    __tree(__tree&& __t, const allocator_type& __a);
-    __tree& operator=(__tree&& __t)
-        _NOEXCEPT_(
-            __node_traits::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<value_compare>::value &&
-            is_nothrow_move_assignable<__node_allocator>::value);
-    ~__tree();
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin()  _NOEXCEPT {return       iterator(__begin_node());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return const_iterator(__begin_node());}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT {return       iterator(__end_node());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT {return const_iterator(__end_node());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT
-        {return _VSTD::min<size_type>(
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+class __tree 
+{ 
+public: 
+    typedef _Tp                                      value_type; 
+    typedef _Compare                                 value_compare; 
+    typedef _Allocator                               allocator_type; 
+ 
+private: 
+    typedef allocator_traits<allocator_type>         __alloc_traits; 
+    typedef typename __make_tree_node_types<value_type, 
+        typename __alloc_traits::void_pointer>::type 
+                                                    _NodeTypes; 
+    typedef typename _NodeTypes::key_type           key_type; 
+public: 
+    typedef typename _NodeTypes::__node_value_type      __node_value_type; 
+    typedef typename _NodeTypes::__container_value_type __container_value_type; 
+ 
+    typedef typename __alloc_traits::pointer         pointer; 
+    typedef typename __alloc_traits::const_pointer   const_pointer; 
+    typedef typename __alloc_traits::size_type       size_type; 
+    typedef typename __alloc_traits::difference_type difference_type; 
+ 
+public: 
+    typedef typename _NodeTypes::__void_pointer        __void_pointer; 
+ 
+    typedef typename _NodeTypes::__node_type           __node; 
+    typedef typename _NodeTypes::__node_pointer        __node_pointer; 
+ 
+    typedef typename _NodeTypes::__node_base_type      __node_base; 
+    typedef typename _NodeTypes::__node_base_pointer   __node_base_pointer; 
+ 
+    typedef typename _NodeTypes::__end_node_type       __end_node_t; 
+    typedef typename _NodeTypes::__end_node_pointer    __end_node_ptr; 
+ 
+    typedef typename _NodeTypes::__parent_pointer      __parent_pointer; 
+    typedef typename _NodeTypes::__iter_pointer        __iter_pointer; 
+ 
+    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator; 
+    typedef allocator_traits<__node_allocator>         __node_traits; 
+ 
+private: 
+    // check for sane allocator pointer rebinding semantics. Rebinding the 
+    // allocator for a new pointer type should be exactly the same as rebinding 
+    // the pointer using 'pointer_traits'. 
+    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value), 
+                  "Allocator does not rebind pointers in a sane manner."); 
+    typedef typename __rebind_alloc_helper<__node_traits, __node_base>::type 
+        __node_base_allocator; 
+    typedef allocator_traits<__node_base_allocator> __node_base_traits; 
+    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value), 
+                 "Allocator does not rebind pointers in a sane manner."); 
+ 
+private: 
+    __iter_pointer                                     __begin_node_; 
+    __compressed_pair<__end_node_t, __node_allocator>  __pair1_; 
+    __compressed_pair<size_type, value_compare>        __pair3_; 
+ 
+public: 
+    _LIBCPP_INLINE_VISIBILITY 
+    __iter_pointer __end_node() _NOEXCEPT 
+    { 
+        return static_cast<__iter_pointer>( 
+                pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first()) 
+        ); 
+    } 
+    _LIBCPP_INLINE_VISIBILITY 
+    __iter_pointer __end_node() const _NOEXCEPT 
+    { 
+        return static_cast<__iter_pointer>( 
+            pointer_traits<__end_node_ptr>::pointer_to( 
+                const_cast<__end_node_t&>(__pair1_.first()) 
+            ) 
+        ); 
+    } 
+    _LIBCPP_INLINE_VISIBILITY 
+          __node_allocator& __node_alloc() _NOEXCEPT {return __pair1_.second();} 
+private: 
+    _LIBCPP_INLINE_VISIBILITY 
+    const __node_allocator& __node_alloc() const _NOEXCEPT 
+        {return __pair1_.second();} 
+    _LIBCPP_INLINE_VISIBILITY 
+          __iter_pointer& __begin_node() _NOEXCEPT {return __begin_node_;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    const __iter_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;} 
+public: 
+    _LIBCPP_INLINE_VISIBILITY 
+    allocator_type __alloc() const _NOEXCEPT 
+        {return allocator_type(__node_alloc());} 
+private: 
+    _LIBCPP_INLINE_VISIBILITY 
+          size_type& size() _NOEXCEPT {return __pair3_.first();} 
+public: 
+    _LIBCPP_INLINE_VISIBILITY 
+    const size_type& size() const _NOEXCEPT {return __pair3_.first();} 
+    _LIBCPP_INLINE_VISIBILITY 
+          value_compare& value_comp() _NOEXCEPT {return __pair3_.second();} 
+    _LIBCPP_INLINE_VISIBILITY 
+    const value_compare& value_comp() const _NOEXCEPT 
+        {return __pair3_.second();} 
+public: 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    __node_pointer __root() const _NOEXCEPT 
+        {return static_cast<__node_pointer>(__end_node()->__left_);} 
+ 
+    __node_base_pointer* __root_ptr() const _NOEXCEPT { 
+        return _VSTD::addressof(__end_node()->__left_); 
+    } 
+ 
+    typedef __tree_iterator<value_type, __node_pointer, difference_type>             iterator; 
+    typedef __tree_const_iterator<value_type, __node_pointer, difference_type> const_iterator; 
+ 
+    explicit __tree(const value_compare& __comp) 
+        _NOEXCEPT_( 
+            is_nothrow_default_constructible<__node_allocator>::value && 
+            is_nothrow_copy_constructible<value_compare>::value); 
+    explicit __tree(const allocator_type& __a); 
+    __tree(const value_compare& __comp, const allocator_type& __a); 
+    __tree(const __tree& __t); 
+    __tree& operator=(const __tree& __t); 
+    template <class _ForwardIterator> 
+        void __assign_unique(_ForwardIterator __first, _ForwardIterator __last); 
+    template <class _InputIterator> 
+        void __assign_multi(_InputIterator __first, _InputIterator __last); 
+    __tree(__tree&& __t) 
+        _NOEXCEPT_( 
+            is_nothrow_move_constructible<__node_allocator>::value && 
+            is_nothrow_move_constructible<value_compare>::value); 
+    __tree(__tree&& __t, const allocator_type& __a); 
+    __tree& operator=(__tree&& __t) 
+        _NOEXCEPT_( 
+            __node_traits::propagate_on_container_move_assignment::value && 
+            is_nothrow_move_assignable<value_compare>::value && 
+            is_nothrow_move_assignable<__node_allocator>::value); 
+    ~__tree(); 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+          iterator begin()  _NOEXCEPT {return       iterator(__begin_node());} 
+    _LIBCPP_INLINE_VISIBILITY 
+    const_iterator begin() const _NOEXCEPT {return const_iterator(__begin_node());} 
+    _LIBCPP_INLINE_VISIBILITY 
+          iterator end() _NOEXCEPT {return       iterator(__end_node());} 
+    _LIBCPP_INLINE_VISIBILITY 
+    const_iterator end() const _NOEXCEPT {return const_iterator(__end_node());} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    size_type max_size() const _NOEXCEPT 
+        {return _VSTD::min<size_type>( 
                 __node_traits::max_size(__node_alloc()),
                 numeric_limits<difference_type >::max());}
-
-    void clear() _NOEXCEPT;
-
-    void swap(__tree& __t)
-#if _LIBCPP_STD_VER <= 11
-        _NOEXCEPT_(
-            __is_nothrow_swappable<value_compare>::value
-            && (!__node_traits::propagate_on_container_swap::value ||
-                 __is_nothrow_swappable<__node_allocator>::value)
-            );
-#else
-        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value);
-#endif
-
-    template <class _Key, class ..._Args>
-    pair<iterator, bool>
-    __emplace_unique_key_args(_Key const&, _Args&&... __args);
-    template <class _Key, class ..._Args>
-    pair<iterator, bool>
-    __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&&...);
-
-    template <class... _Args>
-    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
-
-    template <class... _Args>
-    iterator __emplace_hint_unique_impl(const_iterator __p, _Args&&... __args);
-
-    template <class... _Args>
-    iterator __emplace_multi(_Args&&... __args);
-
-    template <class... _Args>
-    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
-        return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
-                                            __can_extract_key<_Pp, key_type>());
-    }
-
-    template <class _First, class _Second>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<
-        __can_extract_map_key<_First, key_type, __container_value_type>::value,
-        pair<iterator, bool>
-    >::type __emplace_unique(_First&& __f, _Second&& __s) {
-        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
-                                              _VSTD::forward<_Second>(__s));
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
-        return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
-      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
-      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
-      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_hint_unique(const_iterator __p, _Pp&& __x) {
-        return __emplace_hint_unique_extract_key(__p, _VSTD::forward<_Pp>(__x),
-                                            __can_extract_key<_Pp, key_type>());
-    }
-
-    template <class _First, class _Second>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<
-        __can_extract_map_key<_First, key_type, __container_value_type>::value,
-        iterator
-    >::type __emplace_hint_unique(const_iterator __p, _First&& __f, _Second&& __s) {
-        return __emplace_hint_unique_key_args(__p, __f,
-                                              _VSTD::forward<_First>(__f),
-                                              _VSTD::forward<_Second>(__s)).first;
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_hint_unique(const_iterator __p, _Args&&... __args) {
-        return __emplace_hint_unique_impl(__p, _VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_fail_tag) {
-      return __emplace_hint_unique_impl(__p, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_self_tag) {
-      return __emplace_hint_unique_key_args(__p, __x, _VSTD::forward<_Pp>(__x)).first;
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_first_tag) {
-      return __emplace_hint_unique_key_args(__p, __x.first, _VSTD::forward<_Pp>(__x)).first;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(const __container_value_type& __v) {
-        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_unique(const_iterator __p, const __container_value_type& __v) {
-        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), __v).first;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(__container_value_type&& __v) {
-        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), _VSTD::move(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_unique(const_iterator __p, __container_value_type&& __v) {
-        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), _VSTD::move(__v)).first;
-    }
-
-    template <class _Vp, class = typename enable_if<
-            !is_same<typename __unconstref<_Vp>::type,
-                     __container_value_type
-            >::value
-        >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(_Vp&& __v) {
-        return __emplace_unique(_VSTD::forward<_Vp>(__v));
-    }
-
-    template <class _Vp, class = typename enable_if<
-            !is_same<typename __unconstref<_Vp>::type,
-                     __container_value_type
-            >::value
-        >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_unique(const_iterator __p, _Vp&& __v) {
-        return __emplace_hint_unique(__p, _VSTD::forward<_Vp>(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(__container_value_type&& __v) {
-        return __emplace_multi(_VSTD::move(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const_iterator __p, __container_value_type&& __v) {
-        return __emplace_hint_multi(__p, _VSTD::move(__v));
-    }
-
-    template <class _Vp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(_Vp&& __v) {
-        return __emplace_multi(_VSTD::forward<_Vp>(__v));
-    }
-
-    template <class _Vp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const_iterator __p, _Vp&& __v) {
-        return __emplace_hint_multi(__p, _VSTD::forward<_Vp>(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __node_assign_unique(const __container_value_type& __v, __node_pointer __dest);
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_insert_multi(__node_pointer __nd);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_insert_multi(const_iterator __p, __node_pointer __nd);
-
+ 
+    void clear() _NOEXCEPT; 
+ 
+    void swap(__tree& __t) 
+#if _LIBCPP_STD_VER <= 11 
+        _NOEXCEPT_( 
+            __is_nothrow_swappable<value_compare>::value 
+            && (!__node_traits::propagate_on_container_swap::value || 
+                 __is_nothrow_swappable<__node_allocator>::value) 
+            ); 
+#else 
+        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value); 
+#endif 
+ 
+    template <class _Key, class ..._Args> 
+    pair<iterator, bool> 
+    __emplace_unique_key_args(_Key const&, _Args&&... __args); 
+    template <class _Key, class ..._Args> 
+    pair<iterator, bool> 
+    __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&&...); 
+ 
+    template <class... _Args> 
+    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args); 
+ 
+    template <class... _Args> 
+    iterator __emplace_hint_unique_impl(const_iterator __p, _Args&&... __args); 
+ 
+    template <class... _Args> 
+    iterator __emplace_multi(_Args&&... __args); 
+ 
+    template <class... _Args> 
+    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args); 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> __emplace_unique(_Pp&& __x) { 
+        return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x), 
+                                            __can_extract_key<_Pp, key_type>()); 
+    } 
+ 
+    template <class _First, class _Second> 
+    _LIBCPP_INLINE_VISIBILITY 
+    typename enable_if< 
+        __can_extract_map_key<_First, key_type, __container_value_type>::value, 
+        pair<iterator, bool> 
+    >::type __emplace_unique(_First&& __f, _Second&& __s) { 
+        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f), 
+                                              _VSTD::forward<_Second>(__s)); 
+    } 
+ 
+    template <class... _Args> 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> __emplace_unique(_Args&&... __args) { 
+        return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...); 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> 
+    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) { 
+      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x)); 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> 
+    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) { 
+      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x)); 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> 
+    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) { 
+      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x)); 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __emplace_hint_unique(const_iterator __p, _Pp&& __x) { 
+        return __emplace_hint_unique_extract_key(__p, _VSTD::forward<_Pp>(__x), 
+                                            __can_extract_key<_Pp, key_type>()); 
+    } 
+ 
+    template <class _First, class _Second> 
+    _LIBCPP_INLINE_VISIBILITY 
+    typename enable_if< 
+        __can_extract_map_key<_First, key_type, __container_value_type>::value, 
+        iterator 
+    >::type __emplace_hint_unique(const_iterator __p, _First&& __f, _Second&& __s) { 
+        return __emplace_hint_unique_key_args(__p, __f, 
+                                              _VSTD::forward<_First>(__f), 
+                                              _VSTD::forward<_Second>(__s)).first; 
+    } 
+ 
+    template <class... _Args> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __emplace_hint_unique(const_iterator __p, _Args&&... __args) { 
+        return __emplace_hint_unique_impl(__p, _VSTD::forward<_Args>(__args)...); 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator 
+    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_fail_tag) { 
+      return __emplace_hint_unique_impl(__p, _VSTD::forward<_Pp>(__x)); 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator 
+    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_self_tag) { 
+      return __emplace_hint_unique_key_args(__p, __x, _VSTD::forward<_Pp>(__x)).first; 
+    } 
+ 
+    template <class _Pp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator 
+    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_first_tag) { 
+      return __emplace_hint_unique_key_args(__p, __x.first, _VSTD::forward<_Pp>(__x)).first; 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> __insert_unique(const __container_value_type& __v) { 
+        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), __v); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_unique(const_iterator __p, const __container_value_type& __v) { 
+        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), __v).first; 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> __insert_unique(__container_value_type&& __v) { 
+        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), _VSTD::move(__v)); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_unique(const_iterator __p, __container_value_type&& __v) { 
+        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), _VSTD::move(__v)).first; 
+    } 
+ 
+    template <class _Vp, class = typename enable_if< 
+            !is_same<typename __unconstref<_Vp>::type, 
+                     __container_value_type 
+            >::value 
+        >::type> 
+    _LIBCPP_INLINE_VISIBILITY 
+    pair<iterator, bool> __insert_unique(_Vp&& __v) { 
+        return __emplace_unique(_VSTD::forward<_Vp>(__v)); 
+    } 
+ 
+    template <class _Vp, class = typename enable_if< 
+            !is_same<typename __unconstref<_Vp>::type, 
+                     __container_value_type 
+            >::value 
+        >::type> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_unique(const_iterator __p, _Vp&& __v) { 
+        return __emplace_hint_unique(__p, _VSTD::forward<_Vp>(__v)); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_multi(__container_value_type&& __v) { 
+        return __emplace_multi(_VSTD::move(__v)); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_multi(const_iterator __p, __container_value_type&& __v) { 
+        return __emplace_hint_multi(__p, _VSTD::move(__v)); 
+    } 
+ 
+    template <class _Vp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_multi(_Vp&& __v) { 
+        return __emplace_multi(_VSTD::forward<_Vp>(__v)); 
+    } 
+ 
+    template <class _Vp> 
+    _LIBCPP_INLINE_VISIBILITY 
+    iterator __insert_multi(const_iterator __p, _Vp&& __v) { 
+        return __emplace_hint_multi(__p, _VSTD::forward<_Vp>(__v)); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool> __node_assign_unique(const __container_value_type& __v, __node_pointer __dest); 
+ 
+    _LIBCPP_INLINE_VISIBILITY
+    iterator __node_insert_multi(__node_pointer __nd); 
+    _LIBCPP_INLINE_VISIBILITY
+    iterator __node_insert_multi(const_iterator __p, __node_pointer __nd); 
+ 
 
     _LIBCPP_INLINE_VISIBILITY iterator
     __remove_node_pointer(__node_pointer) _NOEXCEPT;
@@ -1351,906 +1351,906 @@ public:
     _NodeHandle __node_handle_extract(const_iterator);
 #endif
 
-    iterator erase(const_iterator __p);
-    iterator erase(const_iterator __f, const_iterator __l);
-    template <class _Key>
-        size_type __erase_unique(const _Key& __k);
-    template <class _Key>
-        size_type __erase_multi(const _Key& __k);
-
-    void __insert_node_at(__parent_pointer     __parent,
-                          __node_base_pointer& __child,
+    iterator erase(const_iterator __p); 
+    iterator erase(const_iterator __f, const_iterator __l); 
+    template <class _Key> 
+        size_type __erase_unique(const _Key& __k); 
+    template <class _Key> 
+        size_type __erase_multi(const _Key& __k); 
+ 
+    void __insert_node_at(__parent_pointer     __parent, 
+                          __node_base_pointer& __child, 
                           __node_base_pointer __new_node) _NOEXCEPT;
-
-    template <class _Key>
-        iterator find(const _Key& __v);
-    template <class _Key>
-        const_iterator find(const _Key& __v) const;
-
-    template <class _Key>
-        size_type __count_unique(const _Key& __k) const;
-    template <class _Key>
-        size_type __count_multi(const _Key& __k) const;
-
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator lower_bound(const _Key& __v)
-            {return __lower_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        iterator __lower_bound(const _Key& __v,
-                               __node_pointer __root,
-                               __iter_pointer __result);
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        const_iterator lower_bound(const _Key& __v) const
-            {return __lower_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        const_iterator __lower_bound(const _Key& __v,
-                                     __node_pointer __root,
-                                     __iter_pointer __result) const;
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator upper_bound(const _Key& __v)
-            {return __upper_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        iterator __upper_bound(const _Key& __v,
-                               __node_pointer __root,
-                               __iter_pointer __result);
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        const_iterator upper_bound(const _Key& __v) const
-            {return __upper_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        const_iterator __upper_bound(const _Key& __v,
-                                     __node_pointer __root,
-                                     __iter_pointer __result) const;
-    template <class _Key>
-        pair<iterator, iterator>
-        __equal_range_unique(const _Key& __k);
-    template <class _Key>
-        pair<const_iterator, const_iterator>
-        __equal_range_unique(const _Key& __k) const;
-
-    template <class _Key>
-        pair<iterator, iterator>
-        __equal_range_multi(const _Key& __k);
-    template <class _Key>
-        pair<const_iterator, const_iterator>
-        __equal_range_multi(const _Key& __k) const;
-
-    typedef __tree_node_destructor<__node_allocator> _Dp;
-    typedef unique_ptr<__node, _Dp> __node_holder;
-
-    __node_holder remove(const_iterator __p) _NOEXCEPT;
-private:
-    __node_base_pointer&
-        __find_leaf_low(__parent_pointer& __parent, const key_type& __v);
-    __node_base_pointer&
-        __find_leaf_high(__parent_pointer& __parent, const key_type& __v);
-    __node_base_pointer&
-        __find_leaf(const_iterator __hint,
-                    __parent_pointer& __parent, const key_type& __v);
-    // FIXME: Make this function const qualified. Unfortunately doing so
-    // breaks existing code which uses non-const callable comparators.
-    template <class _Key>
-    __node_base_pointer&
-        __find_equal(__parent_pointer& __parent, const _Key& __v);
-    template <class _Key>
-    _LIBCPP_INLINE_VISIBILITY __node_base_pointer&
-    __find_equal(__parent_pointer& __parent, const _Key& __v) const {
-      return const_cast<__tree*>(this)->__find_equal(__parent, __v);
-    }
-    template <class _Key>
-    __node_base_pointer&
-        __find_equal(const_iterator __hint, __parent_pointer& __parent,
-                     __node_base_pointer& __dummy,
-                     const _Key& __v);
-
-    template <class ..._Args>
-    __node_holder __construct_node(_Args&& ...__args);
-
-    void destroy(__node_pointer __nd) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __tree& __t)
-        {__copy_assign_alloc(__t, integral_constant<bool,
-             __node_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __tree& __t, true_type)
-        {
-        if (__node_alloc() != __t.__node_alloc())
+ 
+    template <class _Key> 
+        iterator find(const _Key& __v); 
+    template <class _Key> 
+        const_iterator find(const _Key& __v) const; 
+ 
+    template <class _Key> 
+        size_type __count_unique(const _Key& __k) const; 
+    template <class _Key> 
+        size_type __count_multi(const _Key& __k) const; 
+ 
+    template <class _Key> 
+        _LIBCPP_INLINE_VISIBILITY 
+        iterator lower_bound(const _Key& __v) 
+            {return __lower_bound(__v, __root(), __end_node());} 
+    template <class _Key> 
+        iterator __lower_bound(const _Key& __v, 
+                               __node_pointer __root, 
+                               __iter_pointer __result); 
+    template <class _Key> 
+        _LIBCPP_INLINE_VISIBILITY 
+        const_iterator lower_bound(const _Key& __v) const 
+            {return __lower_bound(__v, __root(), __end_node());} 
+    template <class _Key> 
+        const_iterator __lower_bound(const _Key& __v, 
+                                     __node_pointer __root, 
+                                     __iter_pointer __result) const; 
+    template <class _Key> 
+        _LIBCPP_INLINE_VISIBILITY 
+        iterator upper_bound(const _Key& __v) 
+            {return __upper_bound(__v, __root(), __end_node());} 
+    template <class _Key> 
+        iterator __upper_bound(const _Key& __v, 
+                               __node_pointer __root, 
+                               __iter_pointer __result); 
+    template <class _Key> 
+        _LIBCPP_INLINE_VISIBILITY 
+        const_iterator upper_bound(const _Key& __v) const 
+            {return __upper_bound(__v, __root(), __end_node());} 
+    template <class _Key> 
+        const_iterator __upper_bound(const _Key& __v, 
+                                     __node_pointer __root, 
+                                     __iter_pointer __result) const; 
+    template <class _Key> 
+        pair<iterator, iterator> 
+        __equal_range_unique(const _Key& __k); 
+    template <class _Key> 
+        pair<const_iterator, const_iterator> 
+        __equal_range_unique(const _Key& __k) const; 
+ 
+    template <class _Key> 
+        pair<iterator, iterator> 
+        __equal_range_multi(const _Key& __k); 
+    template <class _Key> 
+        pair<const_iterator, const_iterator> 
+        __equal_range_multi(const _Key& __k) const; 
+ 
+    typedef __tree_node_destructor<__node_allocator> _Dp; 
+    typedef unique_ptr<__node, _Dp> __node_holder; 
+ 
+    __node_holder remove(const_iterator __p) _NOEXCEPT; 
+private: 
+    __node_base_pointer& 
+        __find_leaf_low(__parent_pointer& __parent, const key_type& __v); 
+    __node_base_pointer& 
+        __find_leaf_high(__parent_pointer& __parent, const key_type& __v); 
+    __node_base_pointer& 
+        __find_leaf(const_iterator __hint, 
+                    __parent_pointer& __parent, const key_type& __v); 
+    // FIXME: Make this function const qualified. Unfortunately doing so 
+    // breaks existing code which uses non-const callable comparators. 
+    template <class _Key> 
+    __node_base_pointer& 
+        __find_equal(__parent_pointer& __parent, const _Key& __v); 
+    template <class _Key> 
+    _LIBCPP_INLINE_VISIBILITY __node_base_pointer& 
+    __find_equal(__parent_pointer& __parent, const _Key& __v) const { 
+      return const_cast<__tree*>(this)->__find_equal(__parent, __v); 
+    } 
+    template <class _Key> 
+    __node_base_pointer& 
+        __find_equal(const_iterator __hint, __parent_pointer& __parent, 
+                     __node_base_pointer& __dummy, 
+                     const _Key& __v); 
+ 
+    template <class ..._Args> 
+    __node_holder __construct_node(_Args&& ...__args); 
+ 
+    void destroy(__node_pointer __nd) _NOEXCEPT; 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __copy_assign_alloc(const __tree& __t) 
+        {__copy_assign_alloc(__t, integral_constant<bool, 
+             __node_traits::propagate_on_container_copy_assignment::value>());} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __copy_assign_alloc(const __tree& __t, true_type) 
+        { 
+        if (__node_alloc() != __t.__node_alloc()) 
             clear();
-        __node_alloc() = __t.__node_alloc();
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __tree&, false_type) {}
-
-    void __move_assign(__tree& __t, false_type);
-    void __move_assign(__tree& __t, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
-                   is_nothrow_move_assignable<__node_allocator>::value);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__tree& __t)
-        _NOEXCEPT_(
-            !__node_traits::propagate_on_container_move_assignment::value ||
-            is_nothrow_move_assignable<__node_allocator>::value)
-        {__move_assign_alloc(__t, integral_constant<bool,
-             __node_traits::propagate_on_container_move_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__tree& __t, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
-        {__node_alloc() = _VSTD::move(__t.__node_alloc());}
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {}
-
-    struct _DetachedTreeCache {
-      _LIBCPP_INLINE_VISIBILITY
-      explicit _DetachedTreeCache(__tree *__t) _NOEXCEPT : __t_(__t),
-        __cache_root_(__detach_from_tree(__t)) {
-          __advance();
-        }
-
-      _LIBCPP_INLINE_VISIBILITY
-      __node_pointer __get() const _NOEXCEPT {
-        return __cache_elem_;
-      }
-
-      _LIBCPP_INLINE_VISIBILITY
-      void __advance() _NOEXCEPT {
-        __cache_elem_ = __cache_root_;
-        if (__cache_root_) {
-          __cache_root_ = __detach_next(__cache_root_);
-        }
-      }
-
-      _LIBCPP_INLINE_VISIBILITY
-      ~_DetachedTreeCache() {
-        __t_->destroy(__cache_elem_);
-        if (__cache_root_) {
-          while (__cache_root_->__parent_ != nullptr)
-            __cache_root_ = static_cast<__node_pointer>(__cache_root_->__parent_);
-          __t_->destroy(__cache_root_);
-        }
-      }
-
-       _DetachedTreeCache(_DetachedTreeCache const&) = delete;
-       _DetachedTreeCache& operator=(_DetachedTreeCache const&) = delete;
-
-    private:
-      _LIBCPP_INLINE_VISIBILITY
-      static __node_pointer __detach_from_tree(__tree *__t) _NOEXCEPT;
-      _LIBCPP_INLINE_VISIBILITY
-      static __node_pointer __detach_next(__node_pointer) _NOEXCEPT;
-
-      __tree *__t_;
-      __node_pointer __cache_root_;
-      __node_pointer __cache_elem_;
-    };
-
-
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-};
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<__node_allocator>::value &&
-            is_nothrow_copy_constructible<value_compare>::value)
-    : __pair3_(0, __comp)
-{
-    __begin_node() = __end_node();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a)
-    : __begin_node_(__iter_pointer()),
-      __pair1_(__default_init_tag(), __node_allocator(__a)),
-      __pair3_(0, __default_init_tag())
-{
-    __begin_node() = __end_node();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp,
-                                           const allocator_type& __a)
-    : __begin_node_(__iter_pointer()),
-      __pair1_(__default_init_tag(), __node_allocator(__a)),
-      __pair3_(0, __comp)
-{
-    __begin_node() = __end_node();
-}
-
-// Precondition:  size() != 0
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
-__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_from_tree(__tree *__t) _NOEXCEPT
-{
-    __node_pointer __cache = static_cast<__node_pointer>(__t->__begin_node());
-    __t->__begin_node() = __t->__end_node();
-    __t->__end_node()->__left_->__parent_ = nullptr;
-    __t->__end_node()->__left_ = nullptr;
-    __t->size() = 0;
-    // __cache->__left_ == nullptr
-    if (__cache->__right_ != nullptr)
-        __cache = static_cast<__node_pointer>(__cache->__right_);
-    // __cache->__left_ == nullptr
-    // __cache->__right_ == nullptr
-    return __cache;
-}
-
-// Precondition:  __cache != nullptr
-//    __cache->left_ == nullptr
-//    __cache->right_ == nullptr
-//    This is no longer a red-black tree
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
-__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_next(__node_pointer __cache) _NOEXCEPT
-{
-    if (__cache->__parent_ == nullptr)
-        return nullptr;
-    if (_VSTD::__tree_is_left_child(static_cast<__node_base_pointer>(__cache)))
-    {
-        __cache->__parent_->__left_ = nullptr;
-        __cache = static_cast<__node_pointer>(__cache->__parent_);
-        if (__cache->__right_ == nullptr)
-            return __cache;
-        return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__right_));
-    }
-    // __cache is right child
-    __cache->__parent_unsafe()->__right_ = nullptr;
-    __cache = static_cast<__node_pointer>(__cache->__parent_);
-    if (__cache->__left_ == nullptr)
-        return __cache;
-    return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__left_));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>&
-__tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t)
-{
-    if (this != _VSTD::addressof(__t))
-    {
-        value_comp() = __t.value_comp();
-        __copy_assign_alloc(__t);
-        __assign_multi(__t.begin(), __t.end());
-    }
-    return *this;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _ForwardIterator>
-void
-__tree<_Tp, _Compare, _Allocator>::__assign_unique(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef iterator_traits<_ForwardIterator> _ITraits;
-    typedef typename _ITraits::value_type _ItValueType;
-    static_assert((is_same<_ItValueType, __container_value_type>::value),
-                  "__assign_unique may only be called with the containers value type");
-    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value,
-                  "__assign_unique requires a forward iterator");
-    if (size() != 0)
-    {
-        _DetachedTreeCache __cache(this);
-          for (; __cache.__get() != nullptr && __first != __last; ++__first) {
-              if (__node_assign_unique(*__first, __cache.__get()).second)
-                  __cache.__advance();
-            }
-    }
-    for (; __first != __last; ++__first)
-        __insert_unique(*__first);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _InputIterator>
-void
-__tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _InputIterator __last)
-{
-    typedef iterator_traits<_InputIterator> _ITraits;
-    typedef typename _ITraits::value_type _ItValueType;
-    static_assert((is_same<_ItValueType, __container_value_type>::value ||
-                  is_same<_ItValueType, __node_value_type>::value),
-                  "__assign_multi may only be called with the containers value type"
-                  " or the nodes value type");
-    if (size() != 0)
-    {
-        _DetachedTreeCache __cache(this);
-        for (; __cache.__get() && __first != __last; ++__first) {
-            __cache.__get()->__value_ = *__first;
-            __node_insert_multi(__cache.__get());
-            __cache.__advance();
-        }
-    }
-    for (; __first != __last; ++__first)
-        __insert_multi(_NodeTypes::__get_value(*__first));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t)
-    : __begin_node_(__iter_pointer()),
-      __pair1_(__default_init_tag(), __node_traits::select_on_container_copy_construction(__t.__node_alloc())),
-      __pair3_(0, __t.value_comp())
-{
-    __begin_node() = __end_node();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t)
-    _NOEXCEPT_(
-        is_nothrow_move_constructible<__node_allocator>::value &&
-        is_nothrow_move_constructible<value_compare>::value)
-    : __begin_node_(_VSTD::move(__t.__begin_node_)),
-      __pair1_(_VSTD::move(__t.__pair1_)),
-      __pair3_(_VSTD::move(__t.__pair3_))
-{
-    if (size() == 0)
-        __begin_node() = __end_node();
-    else
-    {
-        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-        __t.__begin_node() = __t.__end_node();
-        __t.__end_node()->__left_ = nullptr;
-        __t.size() = 0;
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a)
-    : __pair1_(__default_init_tag(), __node_allocator(__a)),
-      __pair3_(0, _VSTD::move(__t.value_comp()))
-{
-    if (__a == __t.__alloc())
-    {
-        if (__t.size() == 0)
-            __begin_node() = __end_node();
-        else
-        {
-            __begin_node() = __t.__begin_node();
-            __end_node()->__left_ = __t.__end_node()->__left_;
-            __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-            size() = __t.size();
-            __t.__begin_node() = __t.__end_node();
-            __t.__end_node()->__left_ = nullptr;
-            __t.size() = 0;
-        }
-    }
-    else
-    {
-        __begin_node() = __end_node();
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type)
-    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
-               is_nothrow_move_assignable<__node_allocator>::value)
-{
-    destroy(static_cast<__node_pointer>(__end_node()->__left_));
-    __begin_node_ = __t.__begin_node_;
-    __pair1_.first() = __t.__pair1_.first();
-    __move_assign_alloc(__t);
-    __pair3_ = _VSTD::move(__t.__pair3_);
-    if (size() == 0)
-        __begin_node() = __end_node();
-    else
-    {
-        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-        __t.__begin_node() = __t.__end_node();
-        __t.__end_node()->__left_ = nullptr;
-        __t.size() = 0;
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type)
-{
-    if (__node_alloc() == __t.__node_alloc())
-        __move_assign(__t, true_type());
-    else
-    {
-        value_comp() = _VSTD::move(__t.value_comp());
-        const_iterator __e = end();
-        if (size() != 0)
-        {
-            _DetachedTreeCache __cache(this);
-            while (__cache.__get() != nullptr && __t.size() != 0) {
-              __cache.__get()->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_);
-              __node_insert_multi(__cache.__get());
-              __cache.__advance();
-            }
-        }
-        while (__t.size() != 0)
-            __insert_multi(__e, _NodeTypes::__move(__t.remove(__t.begin())->__value_));
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>&
-__tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t)
-    _NOEXCEPT_(
-        __node_traits::propagate_on_container_move_assignment::value &&
-        is_nothrow_move_assignable<value_compare>::value &&
-        is_nothrow_move_assignable<__node_allocator>::value)
-
-{
-    __move_assign(__t, integral_constant<bool,
-                  __node_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::~__tree()
-{
-    static_assert((is_copy_constructible<value_compare>::value),
-                 "Comparator must be copy-constructible.");
-  destroy(__root());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT
-{
-    if (__nd != nullptr)
-    {
-        destroy(static_cast<__node_pointer>(__nd->__left_));
-        destroy(static_cast<__node_pointer>(__nd->__right_));
-        __node_allocator& __na = __node_alloc();
-        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__nd->__value_));
-        __node_traits::deallocate(__na, __nd, 1);
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
-#if _LIBCPP_STD_VER <= 11
-        _NOEXCEPT_(
-            __is_nothrow_swappable<value_compare>::value
-            && (!__node_traits::propagate_on_container_swap::value ||
-                 __is_nothrow_swappable<__node_allocator>::value)
-            )
-#else
-        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value)
-#endif
-{
-    using _VSTD::swap;
-    swap(__begin_node_, __t.__begin_node_);
-    swap(__pair1_.first(), __t.__pair1_.first());
-    _VSTD::__swap_allocator(__node_alloc(), __t.__node_alloc());
-    __pair3_.swap(__t.__pair3_);
-    if (size() == 0)
-        __begin_node() = __end_node();
-    else
-        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-    if (__t.size() == 0)
-        __t.__begin_node() = __t.__end_node();
-    else
-        __t.__end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__t.__end_node());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT
-{
-    destroy(__root());
-    size() = 0;
-    __begin_node() = __end_node();
-    __end_node()->__left_ = nullptr;
-}
-
-// Find lower_bound place to insert
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(__parent_pointer& __parent,
-                                                   const key_type& __v)
-{
-    __node_pointer __nd = __root();
-    if (__nd != nullptr)
-    {
-        while (true)
-        {
-            if (value_comp()(__nd->__value_, __v))
-            {
-                if (__nd->__right_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__right_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __nd->__right_;
-                }
-            }
-            else
-            {
-                if (__nd->__left_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__left_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __parent->__left_;
-                }
-            }
-        }
-    }
-    __parent = static_cast<__parent_pointer>(__end_node());
-    return __parent->__left_;
-}
-
-// Find upper_bound place to insert
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(__parent_pointer& __parent,
-                                                    const key_type& __v)
-{
-    __node_pointer __nd = __root();
-    if (__nd != nullptr)
-    {
-        while (true)
-        {
-            if (value_comp()(__v, __nd->__value_))
-            {
-                if (__nd->__left_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__left_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __parent->__left_;
-                }
+        __node_alloc() = __t.__node_alloc(); 
+        } 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __copy_assign_alloc(const __tree&, false_type) {} 
+ 
+    void __move_assign(__tree& __t, false_type); 
+    void __move_assign(__tree& __t, true_type) 
+        _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value && 
+                   is_nothrow_move_assignable<__node_allocator>::value); 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __move_assign_alloc(__tree& __t) 
+        _NOEXCEPT_( 
+            !__node_traits::propagate_on_container_move_assignment::value || 
+            is_nothrow_move_assignable<__node_allocator>::value) 
+        {__move_assign_alloc(__t, integral_constant<bool, 
+             __node_traits::propagate_on_container_move_assignment::value>());} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __move_assign_alloc(__tree& __t, true_type) 
+        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value) 
+        {__node_alloc() = _VSTD::move(__t.__node_alloc());} 
+    _LIBCPP_INLINE_VISIBILITY 
+    void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {} 
+ 
+    struct _DetachedTreeCache { 
+      _LIBCPP_INLINE_VISIBILITY 
+      explicit _DetachedTreeCache(__tree *__t) _NOEXCEPT : __t_(__t), 
+        __cache_root_(__detach_from_tree(__t)) { 
+          __advance(); 
+        } 
+ 
+      _LIBCPP_INLINE_VISIBILITY 
+      __node_pointer __get() const _NOEXCEPT { 
+        return __cache_elem_; 
+      } 
+ 
+      _LIBCPP_INLINE_VISIBILITY 
+      void __advance() _NOEXCEPT { 
+        __cache_elem_ = __cache_root_; 
+        if (__cache_root_) { 
+          __cache_root_ = __detach_next(__cache_root_); 
+        } 
+      } 
+ 
+      _LIBCPP_INLINE_VISIBILITY 
+      ~_DetachedTreeCache() { 
+        __t_->destroy(__cache_elem_); 
+        if (__cache_root_) { 
+          while (__cache_root_->__parent_ != nullptr) 
+            __cache_root_ = static_cast<__node_pointer>(__cache_root_->__parent_); 
+          __t_->destroy(__cache_root_); 
+        } 
+      } 
+ 
+       _DetachedTreeCache(_DetachedTreeCache const&) = delete; 
+       _DetachedTreeCache& operator=(_DetachedTreeCache const&) = delete; 
+ 
+    private: 
+      _LIBCPP_INLINE_VISIBILITY 
+      static __node_pointer __detach_from_tree(__tree *__t) _NOEXCEPT; 
+      _LIBCPP_INLINE_VISIBILITY 
+      static __node_pointer __detach_next(__node_pointer) _NOEXCEPT; 
+ 
+      __tree *__t_; 
+      __node_pointer __cache_root_; 
+      __node_pointer __cache_elem_; 
+    }; 
+ 
+ 
+    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map; 
+    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap; 
+}; 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp) 
+        _NOEXCEPT_( 
+            is_nothrow_default_constructible<__node_allocator>::value && 
+            is_nothrow_copy_constructible<value_compare>::value) 
+    : __pair3_(0, __comp) 
+{ 
+    __begin_node() = __end_node(); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a) 
+    : __begin_node_(__iter_pointer()), 
+      __pair1_(__default_init_tag(), __node_allocator(__a)), 
+      __pair3_(0, __default_init_tag()) 
+{ 
+    __begin_node() = __end_node(); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp, 
+                                           const allocator_type& __a) 
+    : __begin_node_(__iter_pointer()), 
+      __pair1_(__default_init_tag(), __node_allocator(__a)), 
+      __pair3_(0, __comp) 
+{ 
+    __begin_node() = __end_node(); 
+} 
+ 
+// Precondition:  size() != 0 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_pointer 
+__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_from_tree(__tree *__t) _NOEXCEPT 
+{ 
+    __node_pointer __cache = static_cast<__node_pointer>(__t->__begin_node()); 
+    __t->__begin_node() = __t->__end_node(); 
+    __t->__end_node()->__left_->__parent_ = nullptr; 
+    __t->__end_node()->__left_ = nullptr; 
+    __t->size() = 0; 
+    // __cache->__left_ == nullptr 
+    if (__cache->__right_ != nullptr) 
+        __cache = static_cast<__node_pointer>(__cache->__right_); 
+    // __cache->__left_ == nullptr 
+    // __cache->__right_ == nullptr 
+    return __cache; 
+} 
+ 
+// Precondition:  __cache != nullptr 
+//    __cache->left_ == nullptr 
+//    __cache->right_ == nullptr 
+//    This is no longer a red-black tree 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_pointer 
+__tree<_Tp, _Compare, _Allocator>::_DetachedTreeCache::__detach_next(__node_pointer __cache) _NOEXCEPT 
+{ 
+    if (__cache->__parent_ == nullptr) 
+        return nullptr; 
+    if (_VSTD::__tree_is_left_child(static_cast<__node_base_pointer>(__cache))) 
+    { 
+        __cache->__parent_->__left_ = nullptr; 
+        __cache = static_cast<__node_pointer>(__cache->__parent_); 
+        if (__cache->__right_ == nullptr) 
+            return __cache; 
+        return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__right_)); 
+    } 
+    // __cache is right child 
+    __cache->__parent_unsafe()->__right_ = nullptr; 
+    __cache = static_cast<__node_pointer>(__cache->__parent_); 
+    if (__cache->__left_ == nullptr) 
+        return __cache; 
+    return static_cast<__node_pointer>(_VSTD::__tree_leaf(__cache->__left_)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>& 
+__tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t) 
+{ 
+    if (this != _VSTD::addressof(__t)) 
+    { 
+        value_comp() = __t.value_comp(); 
+        __copy_assign_alloc(__t); 
+        __assign_multi(__t.begin(), __t.end()); 
+    } 
+    return *this; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _ForwardIterator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::__assign_unique(_ForwardIterator __first, _ForwardIterator __last) 
+{ 
+    typedef iterator_traits<_ForwardIterator> _ITraits; 
+    typedef typename _ITraits::value_type _ItValueType; 
+    static_assert((is_same<_ItValueType, __container_value_type>::value), 
+                  "__assign_unique may only be called with the containers value type"); 
+    static_assert(__is_cpp17_forward_iterator<_ForwardIterator>::value, 
+                  "__assign_unique requires a forward iterator"); 
+    if (size() != 0) 
+    { 
+        _DetachedTreeCache __cache(this); 
+          for (; __cache.__get() != nullptr && __first != __last; ++__first) { 
+              if (__node_assign_unique(*__first, __cache.__get()).second) 
+                  __cache.__advance(); 
             }
-            else
-            {
-                if (__nd->__right_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__right_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __nd->__right_;
-                }
-            }
-        }
-    }
-    __parent = static_cast<__parent_pointer>(__end_node());
-    return __parent->__left_;
-}
-
-// Find leaf place to insert closest to __hint
-// First check prior to __hint.
-// Next check after __hint.
-// Next do O(log N) search.
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
-                                               __parent_pointer& __parent,
-                                               const key_type& __v)
-{
-    if (__hint == end() || !value_comp()(*__hint, __v))  // check before
-    {
-        // __v <= *__hint
-        const_iterator __prior = __hint;
-        if (__prior == begin() || !value_comp()(__v, *--__prior))
-        {
-            // *prev(__hint) <= __v <= *__hint
-            if (__hint.__ptr_->__left_ == nullptr)
-            {
-                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-                return __parent->__left_;
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
-                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
-            }
-        }
-        // __v < *prev(__hint)
-        return __find_leaf_high(__parent, __v);
-    }
-    // else __v > *__hint
-    return __find_leaf_low(__parent, __v);
-}
-
-// Find place to insert if __v doesn't exist
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-// If __v exists, set parent to node of __v and return reference to node of __v
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_equal(__parent_pointer& __parent,
-                                                const _Key& __v)
-{
-    __node_pointer __nd = __root();
-    __node_base_pointer* __nd_ptr = __root_ptr();
-    if (__nd != nullptr)
-    {
-        while (true)
-        {
-            if (value_comp()(__v, __nd->__value_))
-            {
-                if (__nd->__left_ != nullptr) {
-                    __nd_ptr = _VSTD::addressof(__nd->__left_);
-                    __nd = static_cast<__node_pointer>(__nd->__left_);
-                } else {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __parent->__left_;
-                }
-            }
-            else if (value_comp()(__nd->__value_, __v))
-            {
-                if (__nd->__right_ != nullptr) {
-                    __nd_ptr = _VSTD::addressof(__nd->__right_);
-                    __nd = static_cast<__node_pointer>(__nd->__right_);
-                } else {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __nd->__right_;
-                }
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__nd);
-                return *__nd_ptr;
-            }
-        }
-    }
-    __parent = static_cast<__parent_pointer>(__end_node());
-    return __parent->__left_;
-}
-
-// Find place to insert if __v doesn't exist
-// First check prior to __hint.
-// Next check after __hint.
-// Next do O(log N) search.
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-// If __v exists, set parent to node of __v and return reference to node of __v
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
-                                                __parent_pointer& __parent,
-                                                __node_base_pointer& __dummy,
-                                                const _Key& __v)
-{
-    if (__hint == end() || value_comp()(__v, *__hint))  // check before
-    {
-        // __v < *__hint
-        const_iterator __prior = __hint;
-        if (__prior == begin() || value_comp()(*--__prior, __v))
-        {
-            // *prev(__hint) < __v < *__hint
-            if (__hint.__ptr_->__left_ == nullptr)
-            {
-                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-                return __parent->__left_;
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
-                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
-            }
-        }
-        // __v <= *prev(__hint)
-        return __find_equal(__parent, __v);
-    }
-    else if (value_comp()(*__hint, __v))  // check after
-    {
-        // *__hint < __v
-        const_iterator __next = _VSTD::next(__hint);
-        if (__next == end() || value_comp()(__v, *__next))
-        {
-            // *__hint < __v < *_VSTD::next(__hint)
-            if (__hint.__get_np()->__right_ == nullptr)
-            {
-                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-                return static_cast<__node_base_pointer>(__hint.__ptr_)->__right_;
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__next.__ptr_);
-                return __parent->__left_;
-            }
-        }
-        // *next(__hint) <= __v
-        return __find_equal(__parent, __v);
-    }
-    // else __v == *__hint
-    __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-    __dummy = static_cast<__node_base_pointer>(__hint.__ptr_);
-    return __dummy;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
+    } 
+    for (; __first != __last; ++__first) 
+        __insert_unique(*__first); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _InputIterator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _InputIterator __last) 
+{ 
+    typedef iterator_traits<_InputIterator> _ITraits; 
+    typedef typename _ITraits::value_type _ItValueType; 
+    static_assert((is_same<_ItValueType, __container_value_type>::value || 
+                  is_same<_ItValueType, __node_value_type>::value), 
+                  "__assign_multi may only be called with the containers value type" 
+                  " or the nodes value type"); 
+    if (size() != 0) 
+    { 
+        _DetachedTreeCache __cache(this); 
+        for (; __cache.__get() && __first != __last; ++__first) { 
+            __cache.__get()->__value_ = *__first; 
+            __node_insert_multi(__cache.__get()); 
+            __cache.__advance(); 
+        } 
+    } 
+    for (; __first != __last; ++__first) 
+        __insert_multi(_NodeTypes::__get_value(*__first)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t) 
+    : __begin_node_(__iter_pointer()), 
+      __pair1_(__default_init_tag(), __node_traits::select_on_container_copy_construction(__t.__node_alloc())), 
+      __pair3_(0, __t.value_comp()) 
+{ 
+    __begin_node() = __end_node(); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t) 
+    _NOEXCEPT_( 
+        is_nothrow_move_constructible<__node_allocator>::value && 
+        is_nothrow_move_constructible<value_compare>::value) 
+    : __begin_node_(_VSTD::move(__t.__begin_node_)), 
+      __pair1_(_VSTD::move(__t.__pair1_)), 
+      __pair3_(_VSTD::move(__t.__pair3_)) 
+{ 
+    if (size() == 0) 
+        __begin_node() = __end_node(); 
+    else 
+    { 
+        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
+        __t.__begin_node() = __t.__end_node(); 
+        __t.__end_node()->__left_ = nullptr; 
+        __t.size() = 0; 
+    } 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a) 
+    : __pair1_(__default_init_tag(), __node_allocator(__a)), 
+      __pair3_(0, _VSTD::move(__t.value_comp())) 
+{ 
+    if (__a == __t.__alloc()) 
+    { 
+        if (__t.size() == 0) 
+            __begin_node() = __end_node(); 
+        else 
+        { 
+            __begin_node() = __t.__begin_node(); 
+            __end_node()->__left_ = __t.__end_node()->__left_; 
+            __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
+            size() = __t.size(); 
+            __t.__begin_node() = __t.__end_node(); 
+            __t.__end_node()->__left_ = nullptr; 
+            __t.size() = 0; 
+        } 
+    } 
+    else 
+    { 
+        __begin_node() = __end_node(); 
+    } 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type) 
+    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value && 
+               is_nothrow_move_assignable<__node_allocator>::value) 
+{ 
+    destroy(static_cast<__node_pointer>(__end_node()->__left_)); 
+    __begin_node_ = __t.__begin_node_; 
+    __pair1_.first() = __t.__pair1_.first(); 
+    __move_assign_alloc(__t); 
+    __pair3_ = _VSTD::move(__t.__pair3_); 
+    if (size() == 0) 
+        __begin_node() = __end_node(); 
+    else 
+    { 
+        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
+        __t.__begin_node() = __t.__end_node(); 
+        __t.__end_node()->__left_ = nullptr; 
+        __t.size() = 0; 
+    } 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type) 
+{ 
+    if (__node_alloc() == __t.__node_alloc()) 
+        __move_assign(__t, true_type()); 
+    else 
+    { 
+        value_comp() = _VSTD::move(__t.value_comp()); 
+        const_iterator __e = end(); 
+        if (size() != 0) 
+        { 
+            _DetachedTreeCache __cache(this); 
+            while (__cache.__get() != nullptr && __t.size() != 0) { 
+              __cache.__get()->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_); 
+              __node_insert_multi(__cache.__get()); 
+              __cache.__advance(); 
+            } 
+        } 
+        while (__t.size() != 0) 
+            __insert_multi(__e, _NodeTypes::__move(__t.remove(__t.begin())->__value_)); 
+    } 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>& 
+__tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t) 
+    _NOEXCEPT_( 
+        __node_traits::propagate_on_container_move_assignment::value && 
+        is_nothrow_move_assignable<value_compare>::value && 
+        is_nothrow_move_assignable<__node_allocator>::value) 
+ 
+{ 
+    __move_assign(__t, integral_constant<bool, 
+                  __node_traits::propagate_on_container_move_assignment::value>()); 
+    return *this; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+__tree<_Tp, _Compare, _Allocator>::~__tree() 
+{ 
+    static_assert((is_copy_constructible<value_compare>::value), 
+                 "Comparator must be copy-constructible."); 
+  destroy(__root()); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT 
+{ 
+    if (__nd != nullptr) 
+    { 
+        destroy(static_cast<__node_pointer>(__nd->__left_)); 
+        destroy(static_cast<__node_pointer>(__nd->__right_)); 
+        __node_allocator& __na = __node_alloc(); 
+        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__nd->__value_)); 
+        __node_traits::deallocate(__na, __nd, 1); 
+    } 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::swap(__tree& __t) 
+#if _LIBCPP_STD_VER <= 11 
+        _NOEXCEPT_( 
+            __is_nothrow_swappable<value_compare>::value 
+            && (!__node_traits::propagate_on_container_swap::value || 
+                 __is_nothrow_swappable<__node_allocator>::value) 
+            ) 
+#else 
+        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value) 
+#endif 
+{ 
+    using _VSTD::swap; 
+    swap(__begin_node_, __t.__begin_node_); 
+    swap(__pair1_.first(), __t.__pair1_.first()); 
+    _VSTD::__swap_allocator(__node_alloc(), __t.__node_alloc()); 
+    __pair3_.swap(__t.__pair3_); 
+    if (size() == 0) 
+        __begin_node() = __end_node(); 
+    else 
+        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node()); 
+    if (__t.size() == 0) 
+        __t.__begin_node() = __t.__end_node(); 
+    else 
+        __t.__end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__t.__end_node()); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+void 
+__tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT 
+{ 
+    destroy(__root()); 
+    size() = 0; 
+    __begin_node() = __end_node(); 
+    __end_node()->__left_ = nullptr; 
+} 
+ 
+// Find lower_bound place to insert 
+// Set __parent to parent of null leaf 
+// Return reference to null leaf 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
+__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(__parent_pointer& __parent, 
+                                                   const key_type& __v) 
+{ 
+    __node_pointer __nd = __root(); 
+    if (__nd != nullptr) 
+    { 
+        while (true) 
+        { 
+            if (value_comp()(__nd->__value_, __v)) 
+            { 
+                if (__nd->__right_ != nullptr) 
+                    __nd = static_cast<__node_pointer>(__nd->__right_); 
+                else 
+                { 
+                    __parent = static_cast<__parent_pointer>(__nd); 
+                    return __nd->__right_; 
+                } 
+            } 
+            else 
+            { 
+                if (__nd->__left_ != nullptr) 
+                    __nd = static_cast<__node_pointer>(__nd->__left_); 
+                else 
+                { 
+                    __parent = static_cast<__parent_pointer>(__nd); 
+                    return __parent->__left_; 
+                } 
+            } 
+        } 
+    } 
+    __parent = static_cast<__parent_pointer>(__end_node()); 
+    return __parent->__left_; 
+} 
+ 
+// Find upper_bound place to insert 
+// Set __parent to parent of null leaf 
+// Return reference to null leaf 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
+__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(__parent_pointer& __parent, 
+                                                    const key_type& __v) 
+{ 
+    __node_pointer __nd = __root(); 
+    if (__nd != nullptr) 
+    { 
+        while (true) 
+        { 
+            if (value_comp()(__v, __nd->__value_)) 
+            { 
+                if (__nd->__left_ != nullptr) 
+                    __nd = static_cast<__node_pointer>(__nd->__left_); 
+                else 
+                { 
+                    __parent = static_cast<__parent_pointer>(__nd); 
+                    return __parent->__left_; 
+                } 
+            } 
+            else 
+            { 
+                if (__nd->__right_ != nullptr) 
+                    __nd = static_cast<__node_pointer>(__nd->__right_); 
+                else 
+                { 
+                    __parent = static_cast<__parent_pointer>(__nd); 
+                    return __nd->__right_; 
+                } 
+            } 
+        } 
+    } 
+    __parent = static_cast<__parent_pointer>(__end_node()); 
+    return __parent->__left_; 
+} 
+ 
+// Find leaf place to insert closest to __hint 
+// First check prior to __hint. 
+// Next check after __hint. 
+// Next do O(log N) search. 
+// Set __parent to parent of null leaf 
+// Return reference to null leaf 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
+__tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint, 
+                                               __parent_pointer& __parent, 
+                                               const key_type& __v) 
+{ 
+    if (__hint == end() || !value_comp()(*__hint, __v))  // check before 
+    { 
+        // __v <= *__hint 
+        const_iterator __prior = __hint; 
+        if (__prior == begin() || !value_comp()(__v, *--__prior)) 
+        { 
+            // *prev(__hint) <= __v <= *__hint 
+            if (__hint.__ptr_->__left_ == nullptr) 
+            { 
+                __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
+                return __parent->__left_; 
+            } 
+            else 
+            { 
+                __parent = static_cast<__parent_pointer>(__prior.__ptr_); 
+                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_; 
+            } 
+        } 
+        // __v < *prev(__hint) 
+        return __find_leaf_high(__parent, __v); 
+    } 
+    // else __v > *__hint 
+    return __find_leaf_low(__parent, __v); 
+} 
+ 
+// Find place to insert if __v doesn't exist 
+// Set __parent to parent of null leaf 
+// Return reference to null leaf 
+// If __v exists, set parent to node of __v and return reference to node of __v 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
+__tree<_Tp, _Compare, _Allocator>::__find_equal(__parent_pointer& __parent, 
+                                                const _Key& __v) 
+{ 
+    __node_pointer __nd = __root(); 
+    __node_base_pointer* __nd_ptr = __root_ptr(); 
+    if (__nd != nullptr) 
+    { 
+        while (true) 
+        { 
+            if (value_comp()(__v, __nd->__value_)) 
+            { 
+                if (__nd->__left_ != nullptr) { 
+                    __nd_ptr = _VSTD::addressof(__nd->__left_); 
+                    __nd = static_cast<__node_pointer>(__nd->__left_); 
+                } else { 
+                    __parent = static_cast<__parent_pointer>(__nd); 
+                    return __parent->__left_; 
+                } 
+            } 
+            else if (value_comp()(__nd->__value_, __v)) 
+            { 
+                if (__nd->__right_ != nullptr) { 
+                    __nd_ptr = _VSTD::addressof(__nd->__right_); 
+                    __nd = static_cast<__node_pointer>(__nd->__right_); 
+                } else { 
+                    __parent = static_cast<__parent_pointer>(__nd); 
+                    return __nd->__right_; 
+                } 
+            } 
+            else 
+            { 
+                __parent = static_cast<__parent_pointer>(__nd); 
+                return *__nd_ptr; 
+            } 
+        } 
+    } 
+    __parent = static_cast<__parent_pointer>(__end_node()); 
+    return __parent->__left_; 
+} 
+ 
+// Find place to insert if __v doesn't exist 
+// First check prior to __hint. 
+// Next check after __hint. 
+// Next do O(log N) search. 
+// Set __parent to parent of null leaf 
+// Return reference to null leaf 
+// If __v exists, set parent to node of __v and return reference to node of __v 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer& 
+__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint, 
+                                                __parent_pointer& __parent, 
+                                                __node_base_pointer& __dummy, 
+                                                const _Key& __v) 
+{ 
+    if (__hint == end() || value_comp()(__v, *__hint))  // check before 
+    { 
+        // __v < *__hint 
+        const_iterator __prior = __hint; 
+        if (__prior == begin() || value_comp()(*--__prior, __v)) 
+        { 
+            // *prev(__hint) < __v < *__hint 
+            if (__hint.__ptr_->__left_ == nullptr) 
+            { 
+                __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
+                return __parent->__left_; 
+            } 
+            else 
+            { 
+                __parent = static_cast<__parent_pointer>(__prior.__ptr_); 
+                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_; 
+            } 
+        } 
+        // __v <= *prev(__hint) 
+        return __find_equal(__parent, __v); 
+    } 
+    else if (value_comp()(*__hint, __v))  // check after 
+    { 
+        // *__hint < __v 
+        const_iterator __next = _VSTD::next(__hint); 
+        if (__next == end() || value_comp()(__v, *__next)) 
+        { 
+            // *__hint < __v < *_VSTD::next(__hint) 
+            if (__hint.__get_np()->__right_ == nullptr) 
+            { 
+                __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
+                return static_cast<__node_base_pointer>(__hint.__ptr_)->__right_; 
+            } 
+            else 
+            { 
+                __parent = static_cast<__parent_pointer>(__next.__ptr_); 
+                return __parent->__left_; 
+            } 
+        } 
+        // *next(__hint) <= __v 
+        return __find_equal(__parent, __v); 
+    } 
+    // else __v == *__hint 
+    __parent = static_cast<__parent_pointer>(__hint.__ptr_); 
+    __dummy = static_cast<__node_base_pointer>(__hint.__ptr_); 
+    return __dummy; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
 void __tree<_Tp, _Compare, _Allocator>::__insert_node_at(
     __parent_pointer __parent, __node_base_pointer& __child,
     __node_base_pointer __new_node) _NOEXCEPT
-{
-    __new_node->__left_   = nullptr;
-    __new_node->__right_  = nullptr;
-    __new_node->__parent_ = __parent;
-    // __new_node->__is_black_ is initialized in __tree_balance_after_insert
-    __child = __new_node;
-    if (__begin_node()->__left_ != nullptr)
-        __begin_node() = static_cast<__iter_pointer>(__begin_node()->__left_);
-    _VSTD::__tree_balance_after_insert(__end_node()->__left_, __child);
-    ++size();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key, class... _Args>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __k);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key, class... _Args>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args(
-    const_iterator __p, _Key const& __k, _Args&&... __args)
-{
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __k);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class ..._Args>
-typename __tree<_Tp, _Compare, _Allocator>::__node_holder
-__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&& ...__args)
-{
-    static_assert(!__is_tree_value_type<_Args...>::value,
-                  "Cannot construct from __value_type");
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
-    __h.get_deleter().__value_constructed = true;
-    return __h;
-}
-
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__emplace_unique_impl(_Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __h->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_impl(const_iterator __p, _Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __h->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-    }
-    return iterator(__r);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__h->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(static_cast<__node_pointer>(__h.release()));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p,
-                                                        _Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__h->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(static_cast<__node_pointer>(__h.release()));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__node_assign_unique(const __container_value_type& __v, __node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, _NodeTypes::__get_key(__v));
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __nd->__value_ = __v;
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-        __r = __nd;
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__nd->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-    return iterator(__nd);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p,
-                                                       __node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__nd->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-    return iterator(__nd);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
+{ 
+    __new_node->__left_   = nullptr; 
+    __new_node->__right_  = nullptr; 
+    __new_node->__parent_ = __parent; 
+    // __new_node->__is_black_ is initialized in __tree_balance_after_insert 
+    __child = __new_node; 
+    if (__begin_node()->__left_ != nullptr) 
+        __begin_node() = static_cast<__iter_pointer>(__begin_node()->__left_); 
+    _VSTD::__tree_balance_after_insert(__end_node()->__left_, __child); 
+    ++size(); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key, class... _Args> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
+__tree<_Tp, _Compare, _Allocator>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args) 
+{ 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_equal(__parent, __k); 
+    __node_pointer __r = static_cast<__node_pointer>(__child); 
+    bool __inserted = false; 
+    if (__child == nullptr) 
+    { 
+        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
+        __r = __h.release(); 
+        __inserted = true; 
+    } 
+    return pair<iterator, bool>(iterator(__r), __inserted); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key, class... _Args> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args( 
+    const_iterator __p, _Key const& __k, _Args&&... __args) 
+{ 
+    __parent_pointer __parent; 
+    __node_base_pointer __dummy; 
+    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __k); 
+    __node_pointer __r = static_cast<__node_pointer>(__child); 
+    bool __inserted = false; 
+    if (__child == nullptr) 
+    { 
+        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
+        __r = __h.release(); 
+        __inserted = true; 
+    } 
+    return pair<iterator, bool>(iterator(__r), __inserted); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class ..._Args> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder 
+__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&& ...__args) 
+{ 
+    static_assert(!__is_tree_value_type<_Args...>::value, 
+                  "Cannot construct from __value_type"); 
+    __node_allocator& __na = __node_alloc(); 
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na)); 
+    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...); 
+    __h.get_deleter().__value_constructed = true; 
+    return __h; 
+} 
+ 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class... _Args> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
+__tree<_Tp, _Compare, _Allocator>::__emplace_unique_impl(_Args&&... __args) 
+{ 
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_equal(__parent, __h->__value_); 
+    __node_pointer __r = static_cast<__node_pointer>(__child); 
+    bool __inserted = false; 
+    if (__child == nullptr) 
+    { 
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
+        __r = __h.release(); 
+        __inserted = true; 
+    } 
+    return pair<iterator, bool>(iterator(__r), __inserted); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class... _Args> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_impl(const_iterator __p, _Args&&... __args) 
+{ 
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
+    __parent_pointer __parent; 
+    __node_base_pointer __dummy; 
+    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __h->__value_); 
+    __node_pointer __r = static_cast<__node_pointer>(__child); 
+    if (__child == nullptr) 
+    { 
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
+        __r = __h.release(); 
+    } 
+    return iterator(__r); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class... _Args> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args) 
+{ 
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__h->__value_)); 
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
+    return iterator(static_cast<__node_pointer>(__h.release())); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class... _Args> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p, 
+                                                        _Args&&... __args) 
+{ 
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...); 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__h->__value_)); 
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get())); 
+    return iterator(static_cast<__node_pointer>(__h.release())); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool> 
+__tree<_Tp, _Compare, _Allocator>::__node_assign_unique(const __container_value_type& __v, __node_pointer __nd) 
+{ 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_equal(__parent, _NodeTypes::__get_key(__v)); 
+    __node_pointer __r = static_cast<__node_pointer>(__child); 
+    bool __inserted = false; 
+    if (__child == nullptr) 
+    { 
+        __nd->__value_ = __v; 
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd)); 
+        __r = __nd; 
+        __inserted = true; 
+    } 
+    return pair<iterator, bool>(iterator(__r), __inserted); 
+} 
+ 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd) 
+{ 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__nd->__value_)); 
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd)); 
+    return iterator(__nd); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p, 
+                                                       __node_pointer __nd) 
+{ 
+    __parent_pointer __parent; 
+    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__nd->__value_)); 
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd)); 
+    return iterator(__nd); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
 __tree<_Tp, _Compare, _Allocator>::__remove_node_pointer(__node_pointer __ptr) _NOEXCEPT
-{
+{ 
     iterator __r(__ptr);
-    ++__r;
+    ++__r; 
     if (__begin_node() == __ptr)
-        __begin_node() = __r.__ptr_;
-    --size();
-    _VSTD::__tree_remove(__end_node()->__left_,
+        __begin_node() = __r.__ptr_; 
+    --size(); 
+    _VSTD::__tree_remove(__end_node()->__left_, 
                          static_cast<__node_base_pointer>(__ptr));
     return __r;
 }
@@ -2277,7 +2277,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
 
     __insert_node_at(__parent, __child,
                      static_cast<__node_base_pointer>(__ptr));
-    __nh.__release_ptr();
+    __nh.__release_ptr(); 
     return _InsertReturnType{iterator(__ptr), true, _NodeHandle()};
 }
 
@@ -2302,7 +2302,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
         __insert_node_at(__parent, __child,
                          static_cast<__node_base_pointer>(__ptr));
         __r = __ptr;
-        __nh.__release_ptr();
+        __nh.__release_ptr(); 
     }
     return iterator(__r);
 }
@@ -2367,7 +2367,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(_NodeHandle&& __nh
     __node_base_pointer& __child = __find_leaf_high(
         __parent, _NodeTypes::__get_key(__ptr->__value_));
     __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
-    __nh.__release_ptr();
+    __nh.__release_ptr(); 
     return iterator(__ptr);
 }
 
@@ -2386,7 +2386,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(
     __node_base_pointer& __child = __find_leaf(__hint, __parent,
                                                _NodeTypes::__get_key(__ptr->__value_));
     __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
-    __nh.__release_ptr();
+    __nh.__release_ptr(); 
     return iterator(__ptr);
 }
 
@@ -2412,7 +2412,7 @@ __tree<_Tp, _Compare, _Allocator>::__node_handle_merge_multi(_Tree& __source)
     }
 }
 
-#endif // _LIBCPP_STD_VER > 14
+#endif // _LIBCPP_STD_VER > 14 
 
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
@@ -2420,329 +2420,329 @@ __tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p)
 {
     __node_pointer __np = __p.__get_np();
     iterator __r = __remove_node_pointer(__np);
-    __node_allocator& __na = __node_alloc();
-    __node_traits::destroy(__na, _NodeTypes::__get_ptr(
-        const_cast<__node_value_type&>(*__p)));
-    __node_traits::deallocate(__na, __np, 1);
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l)
-{
-    while (__f != __l)
-        __f = erase(__f);
-    return iterator(__l.__ptr_);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k)
-{
-    iterator __i = find(__k);
-    if (__i == end())
-        return 0;
-    erase(__i);
-    return 1;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k)
-{
-    pair<iterator, iterator> __p = __equal_range_multi(__k);
-    size_type __r = 0;
-    for (; __p.first != __p.second; ++__r)
-        __p.first = erase(__p.first);
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v)
-{
-    iterator __p = __lower_bound(__v, __root(), __end_node());
-    if (__p != end() && !value_comp()(__v, *__p))
-        return __p;
-    return end();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator
-__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) const
-{
-    const_iterator __p = __lower_bound(__v, __root(), __end_node());
-    if (__p != end() && !value_comp()(__v, *__p))
-        return __p;
-    return end();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const
-{
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return 1;
-    }
-    return 0;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const
-{
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _VSTD::distance(
-                __lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
-                __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)
-            );
-    }
-    return 0;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result)
-{
-    while (__root != nullptr)
-    {
-        if (!value_comp()(__root->__value_, __v))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator
-__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result) const
-{
-    while (__root != nullptr)
-    {
-        if (!value_comp()(__root->__value_, __v))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return const_iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result)
-{
-    while (__root != nullptr)
-    {
-        if (value_comp()(__v, __root->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator
-__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result) const
-{
-    while (__root != nullptr)
-    {
-        if (value_comp()(__v, __root->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return const_iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k)
-{
-    typedef pair<iterator, iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(iterator(__rt),
-                      iterator(
-                          __rt->__right_ != nullptr ?
-                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_))
-                            : __result));
-    }
-    return _Pp(iterator(__result), iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const
-{
-    typedef pair<const_iterator, const_iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(const_iterator(__rt),
-                      const_iterator(
-                          __rt->__right_ != nullptr ?
-                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_))
-                            : __result));
-    }
-    return _Pp(const_iterator(__result), const_iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k)
-{
-    typedef pair<iterator, iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
-                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
-    }
-    return _Pp(iterator(__result), iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const
-{
-    typedef pair<const_iterator, const_iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
-                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
-    }
-    return _Pp(const_iterator(__result), const_iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_holder
-__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT
-{
-    __node_pointer __np = __p.__get_np();
-    if (__begin_node() == __p.__ptr_)
-    {
-        if (__np->__right_ != nullptr)
-            __begin_node() = static_cast<__iter_pointer>(__np->__right_);
-        else
-            __begin_node() = static_cast<__iter_pointer>(__np->__parent_);
-    }
-    --size();
-    _VSTD::__tree_remove(__end_node()->__left_,
+    __node_allocator& __na = __node_alloc(); 
+    __node_traits::destroy(__na, _NodeTypes::__get_ptr( 
+        const_cast<__node_value_type&>(*__p))); 
+    __node_traits::deallocate(__na, __np, 1); 
+    return __r; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l) 
+{ 
+    while (__f != __l) 
+        __f = erase(__f); 
+    return iterator(__l.__ptr_); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::size_type 
+__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k) 
+{ 
+    iterator __i = find(__k); 
+    if (__i == end()) 
+        return 0; 
+    erase(__i); 
+    return 1; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::size_type 
+__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k) 
+{ 
+    pair<iterator, iterator> __p = __equal_range_multi(__k); 
+    size_type __r = 0; 
+    for (; __p.first != __p.second; ++__r) 
+        __p.first = erase(__p.first); 
+    return __r; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) 
+{ 
+    iterator __p = __lower_bound(__v, __root(), __end_node()); 
+    if (__p != end() && !value_comp()(__v, *__p)) 
+        return __p; 
+    return end(); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator 
+__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) const 
+{ 
+    const_iterator __p = __lower_bound(__v, __root(), __end_node()); 
+    if (__p != end() && !value_comp()(__v, *__p)) 
+        return __p; 
+    return end(); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::size_type 
+__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const 
+{ 
+    __node_pointer __rt = __root(); 
+    while (__rt != nullptr) 
+    { 
+        if (value_comp()(__k, __rt->__value_)) 
+        { 
+            __rt = static_cast<__node_pointer>(__rt->__left_); 
+        } 
+        else if (value_comp()(__rt->__value_, __k)) 
+            __rt = static_cast<__node_pointer>(__rt->__right_); 
+        else 
+            return 1; 
+    } 
+    return 0; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::size_type 
+__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const 
+{ 
+    __iter_pointer __result = __end_node(); 
+    __node_pointer __rt = __root(); 
+    while (__rt != nullptr) 
+    { 
+        if (value_comp()(__k, __rt->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__rt); 
+            __rt = static_cast<__node_pointer>(__rt->__left_); 
+        } 
+        else if (value_comp()(__rt->__value_, __k)) 
+            __rt = static_cast<__node_pointer>(__rt->__right_); 
+        else 
+            return _VSTD::distance( 
+                __lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)), 
+                __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result) 
+            ); 
+    } 
+    return 0; 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v, 
+                                                 __node_pointer __root, 
+                                                 __iter_pointer __result) 
+{ 
+    while (__root != nullptr) 
+    { 
+        if (!value_comp()(__root->__value_, __v)) 
+        { 
+            __result = static_cast<__iter_pointer>(__root); 
+            __root = static_cast<__node_pointer>(__root->__left_); 
+        } 
+        else 
+            __root = static_cast<__node_pointer>(__root->__right_); 
+    } 
+    return iterator(__result); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator 
+__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v, 
+                                                 __node_pointer __root, 
+                                                 __iter_pointer __result) const 
+{ 
+    while (__root != nullptr) 
+    { 
+        if (!value_comp()(__root->__value_, __v)) 
+        { 
+            __result = static_cast<__iter_pointer>(__root); 
+            __root = static_cast<__node_pointer>(__root->__left_); 
+        } 
+        else 
+            __root = static_cast<__node_pointer>(__root->__right_); 
+    } 
+    return const_iterator(__result); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::iterator 
+__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v, 
+                                                 __node_pointer __root, 
+                                                 __iter_pointer __result) 
+{ 
+    while (__root != nullptr) 
+    { 
+        if (value_comp()(__v, __root->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__root); 
+            __root = static_cast<__node_pointer>(__root->__left_); 
+        } 
+        else 
+            __root = static_cast<__node_pointer>(__root->__right_); 
+    } 
+    return iterator(__result); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator 
+__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v, 
+                                                 __node_pointer __root, 
+                                                 __iter_pointer __result) const 
+{ 
+    while (__root != nullptr) 
+    { 
+        if (value_comp()(__v, __root->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__root); 
+            __root = static_cast<__node_pointer>(__root->__left_); 
+        } 
+        else 
+            __root = static_cast<__node_pointer>(__root->__right_); 
+    } 
+    return const_iterator(__result); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, 
+     typename __tree<_Tp, _Compare, _Allocator>::iterator> 
+__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) 
+{ 
+    typedef pair<iterator, iterator> _Pp; 
+    __iter_pointer __result = __end_node(); 
+    __node_pointer __rt = __root(); 
+    while (__rt != nullptr) 
+    { 
+        if (value_comp()(__k, __rt->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__rt); 
+            __rt = static_cast<__node_pointer>(__rt->__left_); 
+        } 
+        else if (value_comp()(__rt->__value_, __k)) 
+            __rt = static_cast<__node_pointer>(__rt->__right_); 
+        else 
+            return _Pp(iterator(__rt), 
+                      iterator( 
+                          __rt->__right_ != nullptr ? 
+                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_)) 
+                            : __result)); 
+    } 
+    return _Pp(iterator(__result), iterator(__result)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator, 
+     typename __tree<_Tp, _Compare, _Allocator>::const_iterator> 
+__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const 
+{ 
+    typedef pair<const_iterator, const_iterator> _Pp; 
+    __iter_pointer __result = __end_node(); 
+    __node_pointer __rt = __root(); 
+    while (__rt != nullptr) 
+    { 
+        if (value_comp()(__k, __rt->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__rt); 
+            __rt = static_cast<__node_pointer>(__rt->__left_); 
+        } 
+        else if (value_comp()(__rt->__value_, __k)) 
+            __rt = static_cast<__node_pointer>(__rt->__right_); 
+        else 
+            return _Pp(const_iterator(__rt), 
+                      const_iterator( 
+                          __rt->__right_ != nullptr ? 
+                              static_cast<__iter_pointer>(_VSTD::__tree_min(__rt->__right_)) 
+                            : __result)); 
+    } 
+    return _Pp(const_iterator(__result), const_iterator(__result)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, 
+     typename __tree<_Tp, _Compare, _Allocator>::iterator> 
+__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) 
+{ 
+    typedef pair<iterator, iterator> _Pp; 
+    __iter_pointer __result = __end_node(); 
+    __node_pointer __rt = __root(); 
+    while (__rt != nullptr) 
+    { 
+        if (value_comp()(__k, __rt->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__rt); 
+            __rt = static_cast<__node_pointer>(__rt->__left_); 
+        } 
+        else if (value_comp()(__rt->__value_, __k)) 
+            __rt = static_cast<__node_pointer>(__rt->__right_); 
+        else 
+            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)), 
+                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)); 
+    } 
+    return _Pp(iterator(__result), iterator(__result)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+template <class _Key> 
+pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator, 
+     typename __tree<_Tp, _Compare, _Allocator>::const_iterator> 
+__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const 
+{ 
+    typedef pair<const_iterator, const_iterator> _Pp; 
+    __iter_pointer __result = __end_node(); 
+    __node_pointer __rt = __root(); 
+    while (__rt != nullptr) 
+    { 
+        if (value_comp()(__k, __rt->__value_)) 
+        { 
+            __result = static_cast<__iter_pointer>(__rt); 
+            __rt = static_cast<__node_pointer>(__rt->__left_); 
+        } 
+        else if (value_comp()(__rt->__value_, __k)) 
+            __rt = static_cast<__node_pointer>(__rt->__right_); 
+        else 
+            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)), 
+                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)); 
+    } 
+    return _Pp(const_iterator(__result), const_iterator(__result)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder 
+__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT 
+{ 
+    __node_pointer __np = __p.__get_np(); 
+    if (__begin_node() == __p.__ptr_) 
+    { 
+        if (__np->__right_ != nullptr) 
+            __begin_node() = static_cast<__iter_pointer>(__np->__right_); 
+        else 
+            __begin_node() = static_cast<__iter_pointer>(__np->__parent_); 
+    } 
+    --size(); 
+    _VSTD::__tree_remove(__end_node()->__left_, 
                          static_cast<__node_base_pointer>(__np));
-    return __node_holder(__np, _Dp(__node_alloc(), true));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__tree<_Tp, _Compare, _Allocator>& __x,
-     __tree<_Tp, _Compare, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP___TREE
+    return __node_holder(__np, _Dp(__node_alloc(), true)); 
+} 
+ 
+template <class _Tp, class _Compare, class _Allocator> 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+swap(__tree<_Tp, _Compare, _Allocator>& __x, 
+     __tree<_Tp, _Compare, _Allocator>& __y) 
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) 
+{ 
+    __x.swap(__y); 
+} 
+ 
+_LIBCPP_END_NAMESPACE_STD 
+ 
+_LIBCPP_POP_MACROS 
+ 
+#endif // _LIBCPP___TREE