MFC r309124:

Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0.  Also completely revamp the build system for
clang, llvm, lldb and their related tools.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.

Relnotes:	yes

MFC r309147:

Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):

  [PPC] Set SP after loading data from stack frame, if no red zone is
  present

  Follow-up to r280705: Make sure that the SP is only restored after
  all data is loaded from the stack frame, if there is no red zone.

  This completes the fix for
  https://llvm.org/bugs/show_bug.cgi?id=26519.

  Differential Revision: https://reviews.llvm.org/D24466

Reported by:    Mark Millard
PR:             214433

MFC r309149:

Pull in r283060 from upstream llvm trunk (by Hal Finkel):

  [PowerPC] Refactor soft-float support, and enable PPC64 soft float

  This change enables soft-float for PowerPC64, and also makes
  soft-float disable all vector instruction sets for both 32-bit and
  64-bit modes. This latter part is necessary because the PPC backend
  canonicalizes many Altivec vector types to floating-point types, and
  so soft-float breaks scalarization support for many operations. Both
  for embedded targets and for operating-system kernels desiring
  soft-float support, it seems reasonable that disabling hardware
  floating-point also disables vector instructions (embedded targets
  without hardware floating point support are unlikely to have Altivec,
  etc. and operating system kernels desiring not to use floating-point
  registers to lower syscall cost are unlikely to want to use vector
  registers either). If someone needs this to work, we'll need to
  change the fact that we promote many Altivec operations to act on
  v4f32. To make it possible to disable Altivec when soft-float is
  enabled, hardware floating-point support needs to be expressed as a
  positive feature, like the others, and not a negative feature,
  because target features cannot have dependencies on the disabling of
  some other feature. So +soft-float has now become -hard-float.

  Fixes PR26970.

Pull in r283061 from upstream clang trunk (by Hal Finkel):

  [PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float

  Enable soft-float support on PPC64, as the backend now supports it.
  Also, the backend now uses -hard-float instead of +soft-float, so set
  the target features accordingly.

  Fixes PR26970.

Reported by:	Mark Millard
PR:		214433

MFC r309212:

Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.

MFC r309262:

Fix packaging for clang, lldb and lld 3.9.0

During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.

Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package

Reviewed by:	gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666

MFC r309656:

During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp.  This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.

Reported by:	Mark Millard
PR:		214902

MFC r309835:

Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.

Reported by:	https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/

MFC r310194:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>

Relnotes:	yes

1 files changed, 847 insertions, 492 deletions

diff --git a/contrib/libc++/include/__tree b/contrib/libc++/include/__tree
index 94565bc..b560bf0 100644
--- a/contrib/libc++/include/__tree
+++ b/contrib/libc++/include/__tree
@@ -29,6 +29,22 @@ template <class _Tp, class _NodePtr, class _DiffType>
 template <class _Tp, class _ConstNodePtr, class _DiffType>
     class _LIBCPP_TYPE_VIS_ONLY __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;
+
+#ifndef _LIBCPP_CXX03_LANG
+template <class _Key, class _Value>
+union __value_type;
+#else
+template <class _Key, class _Value>
+struct __value_type;
+#endif
+
+template <class _Allocator> class __map_node_destructor;
+template <class _TreeIterator> class _LIBCPP_TYPE_VIS_ONLY __map_iterator;
+template <class _TreeIterator> class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator;
+
 /*
 
 _NodePtr algorithms
@@ -149,21 +165,36 @@ __tree_next(_NodePtr __x) _NOEXCEPT
     if (__x->__right_ != nullptr)
         return __tree_min(__x->__right_);
     while (!__tree_is_left_child(__x))
-        __x = __x->__parent_;
-    return __x->__parent_;
+        __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>(__tree_min(__x->__right_));
+    while (!__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.
-template <class _NodePtr>
+// Note: __x may be the end node.
+template <class _NodePtr, class _EndNodePtr>
+inline _LIBCPP_INLINE_VISIBILITY
 _NodePtr
-__tree_prev(_NodePtr __x) _NOEXCEPT
+__tree_prev_iter(_EndNodePtr __x) _NOEXCEPT
 {
     if (__x->__left_ != nullptr)
         return __tree_max(__x->__left_);
-    while (__tree_is_left_child(__x))
-        __x = __x->__parent_;
-    return __x->__parent_;
+    _NodePtr __xx = static_cast<_NodePtr>(__x);
+    while (__tree_is_left_child(__xx))
+        __xx = __xx->__parent_unsafe();
+    return __xx->__parent_unsafe();
 }
 
 // Returns:  pointer to a node which has no children
@@ -199,14 +230,14 @@ __tree_left_rotate(_NodePtr __x) _NOEXCEPT
     _NodePtr __y = __x->__right_;
     __x->__right_ = __y->__left_;
     if (__x->__right_ != nullptr)
-        __x->__right_->__parent_ = __x;
+        __x->__right_->__set_parent(__x);
     __y->__parent_ = __x->__parent_;
     if (__tree_is_left_child(__x))
         __x->__parent_->__left_ = __y;
     else
-        __x->__parent_->__right_ = __y;
+        __x->__parent_unsafe()->__right_ = __y;
     __y->__left_ = __x;
-    __x->__parent_ = __y;
+    __x->__set_parent(__y);
 }
 
 // Effects:  Makes __x->__left_ the subtree root with __x as its right child
@@ -219,14 +250,14 @@ __tree_right_rotate(_NodePtr __x) _NOEXCEPT
     _NodePtr __y = __x->__left_;
     __x->__left_ = __y->__right_;
     if (__x->__left_ != nullptr)
-        __x->__left_->__parent_ = __x;
+        __x->__left_->__set_parent(__x);
     __y->__parent_ = __x->__parent_;
     if (__tree_is_left_child(__x))
         __x->__parent_->__left_ = __y;
     else
-        __x->__parent_->__right_ = __y;
+        __x->__parent_unsafe()->__right_ = __y;
     __y->__right_ = __x;
-    __x->__parent_ = __y;
+    __x->__set_parent(__y);
 }
 
 // Effects:  Rebalances __root after attaching __x to a leaf.
@@ -242,17 +273,17 @@ void
 __tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
 {
     __x->__is_black_ = __x == __root;
-    while (__x != __root && !__x->__parent_->__is_black_)
+    while (__x != __root && !__x->__parent_unsafe()->__is_black_)
     {
         // __x->__parent_ != __root because __x->__parent_->__is_black == false
-        if (__tree_is_left_child(__x->__parent_))
+        if (__tree_is_left_child(__x->__parent_unsafe()))
         {
-            _NodePtr __y = __x->__parent_->__parent_->__right_;
+            _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_;
             if (__y != nullptr && !__y->__is_black_)
             {
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = true;
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = __x == __root;
                 __y->__is_black_ = true;
             }
@@ -260,12 +291,12 @@ __tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
             {
                 if (!__tree_is_left_child(__x))
                 {
-                    __x = __x->__parent_;
+                    __x = __x->__parent_unsafe();
                     __tree_left_rotate(__x);
                 }
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = true;
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = false;
                 __tree_right_rotate(__x);
                 break;
@@ -273,12 +304,12 @@ __tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
         }
         else
         {
-            _NodePtr __y = __x->__parent_->__parent_->__left_;
+            _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_;
             if (__y != nullptr && !__y->__is_black_)
             {
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = true;
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = __x == __root;
                 __y->__is_black_ = true;
             }
@@ -286,12 +317,12 @@ __tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
             {
                 if (__tree_is_left_child(__x))
                 {
-                    __x = __x->__parent_;
+                    __x = __x->__parent_unsafe();
                     __tree_right_rotate(__x);
                 }
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = true;
-                __x = __x->__parent_;
+                __x = __x->__parent_unsafe();
                 __x->__is_black_ = false;
                 __tree_left_rotate(__x);
                 break;
@@ -328,13 +359,13 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
     {
         __y->__parent_->__left_ = __x;
         if (__y != __root)
-            __w = __y->__parent_->__right_;
+            __w = __y->__parent_unsafe()->__right_;
         else
             __root = __x;  // __w == nullptr
     }
     else
     {
-        __y->__parent_->__right_ = __x;
+        __y->__parent_unsafe()->__right_ = __x;
         // __y can't be root if it is a right child
         __w = __y->__parent_->__left_;
     }
@@ -348,12 +379,12 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
         if (__tree_is_left_child(__z))
             __y->__parent_->__left_ = __y;
         else
-            __y->__parent_->__right_ = __y;
+            __y->__parent_unsafe()->__right_ = __y;
         __y->__left_ = __z->__left_;
-        __y->__left_->__parent_ = __y;
+        __y->__left_->__set_parent(__y);
         __y->__right_ = __z->__right_;
         if (__y->__right_ != nullptr)
-            __y->__right_->__parent_ = __y;
+            __y->__right_->__set_parent(__y);
         __y->__is_black_ = __z->__is_black_;
         if (__root == __z)
             __root = __y;
@@ -390,8 +421,8 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                     if (!__w->__is_black_)
                     {
                         __w->__is_black_ = true;
-                        __w->__parent_->__is_black_ = false;
-                        __tree_left_rotate(__w->__parent_);
+                        __w->__parent_unsafe()->__is_black_ = false;
+                        __tree_left_rotate(__w->__parent_unsafe());
                         // __x is still valid
                         // reset __root only if necessary
                         if (__root == __w->__left_)
@@ -404,7 +435,7 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                         (__w->__right_ == nullptr || __w->__right_->__is_black_))
                     {
                         __w->__is_black_ = false;
-                        __x = __w->__parent_;
+                        __x = __w->__parent_unsafe();
                         // __x can no longer be null
                         if (__x == __root || !__x->__is_black_)
                         {
@@ -413,7 +444,7 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                         }
                         // reset sibling, and it still can't be null
                         __w = __tree_is_left_child(__x) ?
-                                    __x->__parent_->__right_ :
+                                    __x->__parent_unsafe()->__right_ :
                                     __x->__parent_->__left_;
                         // continue;
                     }
@@ -427,13 +458,13 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                             __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_;
+                            __w = __w->__parent_unsafe();
                         }
                         // __w has a right red child, left child may be null
-                        __w->__is_black_ = __w->__parent_->__is_black_;
-                        __w->__parent_->__is_black_ = true;
+                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
+                        __w->__parent_unsafe()->__is_black_ = true;
                         __w->__right_->__is_black_ = true;
-                        __tree_left_rotate(__w->__parent_);
+                        __tree_left_rotate(__w->__parent_unsafe());
                         break;
                     }
                 }
@@ -442,8 +473,8 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                     if (!__w->__is_black_)
                     {
                         __w->__is_black_ = true;
-                        __w->__parent_->__is_black_ = false;
-                        __tree_right_rotate(__w->__parent_);
+                        __w->__parent_unsafe()->__is_black_ = false;
+                        __tree_right_rotate(__w->__parent_unsafe());
                         // __x is still valid
                         // reset __root only if necessary
                         if (__root == __w->__right_)
@@ -456,7 +487,7 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                         (__w->__right_ == nullptr || __w->__right_->__is_black_))
                     {
                         __w->__is_black_ = false;
-                        __x = __w->__parent_;
+                        __x = __w->__parent_unsafe();
                         // __x can no longer be null
                         if (!__x->__is_black_ || __x == __root)
                         {
@@ -465,7 +496,7 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                         }
                         // reset sibling, and it still can't be null
                         __w = __tree_is_left_child(__x) ?
-                                    __x->__parent_->__right_ :
+                                    __x->__parent_unsafe()->__right_ :
                                     __x->__parent_->__left_;
                         // continue;
                     }
@@ -479,13 +510,13 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
                             __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_;
+                            __w = __w->__parent_unsafe();
                         }
                         // __w has a left red child, right child may be null
-                        __w->__is_black_ = __w->__parent_->__is_black_;
-                        __w->__parent_->__is_black_ = true;
+                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
+                        __w->__parent_unsafe()->__is_black_ = true;
                         __w->__left_->__is_black_ = true;
-                        __tree_right_rotate(__w->__parent_);
+                        __tree_right_rotate(__w->__parent_unsafe());
                         break;
                     }
                 }
@@ -494,41 +525,182 @@ __tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
     }
 }
 
-template <class _Allocator> class __map_node_destructor;
+// node traits
+
+
+#ifndef _LIBCPP_CXX03_LANG
+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> {};
+#endif
+
+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);
+  }
+
+#ifndef _LIBCPP_CXX03_LANG
+  _LIBCPP_INLINE_VISIBILITY
+  static  __container_value_type&& __move(__node_value_type& __v) {
+    return _VSTD::move(__v);
+  }
+#endif
+};
+
+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 pair<_Key, _Tp>                              __nc_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.__cc.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.__cc;
+  }
+
+  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.__cc);
+  }
+
+#ifndef _LIBCPP_CXX03_LANG
+  _LIBCPP_INLINE_VISIBILITY
+  static  __nc_value_type&& __move(__node_value_type& __v) {
+    return _VSTD::move(__v.__nc);
+  }
+#endif
+};
+
+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
 
-template <class _Allocator>
-class __tree_node_destructor
-{
-    typedef _Allocator                                      allocator_type;
-    typedef allocator_traits<allocator_type>                __alloc_traits;
-    typedef typename __alloc_traits::value_type::value_type value_type;
-public:
-    typedef typename __alloc_traits::pointer                pointer;
 private:
+  static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
+                  "_VoidPtr does not point to unqualified void type");
+};
 
-    allocator_type& __na_;
+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;
+};
 
-    __tree_node_destructor& operator=(const __tree_node_destructor&);
+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:
-    bool __value_constructed;
 
-    _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_, _VSTD::addressof(__p->__value_));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
+  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> friend class __map_node_destructor;
+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
@@ -546,26 +718,30 @@ public:
 
 template <class _VoidPtr>
 class __tree_node_base
-    : public __tree_end_node
-             <
-                typename __rebind_pointer<_VoidPtr, __tree_node_base<_VoidPtr> >::type
-             >
+    : public __tree_node_base_types<_VoidPtr>::__end_node_type
 {
-    __tree_node_base(const __tree_node_base&);
-    __tree_node_base& operator=(const __tree_node_base&);
-public:
-    typedef typename __rebind_pointer<_VoidPtr, __tree_node_base>::type pointer;
-    typedef typename __rebind_pointer<_VoidPtr, const __tree_node_base>::type const_pointer;
+    typedef __tree_node_base_types<_VoidPtr> _NodeBaseTypes;
 
-    typedef __tree_end_node<pointer> base;
+public:
+    typedef typename _NodeBaseTypes::__node_base_pointer pointer;
+    typedef typename _NodeBaseTypes::__parent_pointer __parent_pointer;
 
-    pointer __right_;
-    pointer __parent_;
+    pointer          __right_;
+    __parent_pointer __parent_;
     bool __is_black_;
 
     _LIBCPP_INLINE_VISIBILITY
-    __tree_node_base() _NOEXCEPT
-        : __right_(), __parent_(), __is_black_(false) {}
+    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() _LIBCPP_EQUAL_DELETE;
+  __tree_node_base(__tree_node_base const&) _LIBCPP_EQUAL_DELETE;
+  __tree_node_base& operator=(__tree_node_base const&) _LIBCPP_EQUAL_DELETE;
 };
 
 template <class _Tp, class _VoidPtr>
@@ -573,41 +749,71 @@ class __tree_node
     : public __tree_node_base<_VoidPtr>
 {
 public:
-    typedef __tree_node_base<_VoidPtr> base;
-    typedef _Tp value_type;
+    typedef _Tp __node_value_type;
 
-    value_type __value_;
+    __node_value_type __value_;
+
+private:
+  ~__tree_node() _LIBCPP_EQUAL_DELETE;
+  __tree_node(__tree_node const&) _LIBCPP_EQUAL_DELETE;
+  __tree_node& operator=(__tree_node const&) _LIBCPP_EQUAL_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_;
+
+    __tree_node_destructor& operator=(const __tree_node_destructor&);
+
+public:
+    bool __value_constructed;
 
-#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-    template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tree_node(_Args&& ...__args)
-            : __value_(_VSTD::forward<_Args>(__args)...) {}
-#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
     _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_node(const value_type& __v)
-            : __value_(__v) {}
-#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    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;
 };
 
-template <class _TreeIterator> class _LIBCPP_TYPE_VIS_ONLY __map_iterator;
-template <class _TreeIterator> class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator;
 
 template <class _Tp, class _NodePtr, class _DiffType>
 class _LIBCPP_TYPE_VIS_ONLY __tree_iterator
 {
-    typedef _NodePtr                                              __node_pointer;
-    typedef typename pointer_traits<__node_pointer>::element_type __node;
+    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;
 
-    __node_pointer __ptr_;
+    __iter_pointer __ptr_;
 
-    typedef pointer_traits<__node_pointer> __pointer_traits;
 public:
-    typedef bidirectional_iterator_tag iterator_category;
-    typedef _Tp                        value_type;
-    typedef _DiffType                  difference_type;
-    typedef value_type&                reference;
-    typedef typename __rebind_pointer<__node_pointer, value_type>::type pointer;
+    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
@@ -615,14 +821,15 @@ public:
 #endif
     {}
 
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return __ptr_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const
+        {return __get_np()->__value_;}
     _LIBCPP_INLINE_VISIBILITY pointer operator->() const
-        {return pointer_traits<pointer>::pointer_to(__ptr_->__value_);}
+        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
 
     _LIBCPP_INLINE_VISIBILITY
     __tree_iterator& operator++() {
-      __ptr_ = static_cast<__node_pointer>(
-          __tree_next(static_cast<typename __node::base::pointer>(__ptr_)));
+      __ptr_ = static_cast<__iter_pointer>(
+          __tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
       return *this;
     }
     _LIBCPP_INLINE_VISIBILITY
@@ -631,8 +838,8 @@ public:
 
     _LIBCPP_INLINE_VISIBILITY
     __tree_iterator& operator--() {
-      __ptr_ = static_cast<__node_pointer>(
-          __tree_prev(static_cast<typename __node::base::pointer>(__ptr_)));
+      __ptr_ = static_cast<__iter_pointer>(__tree_prev_iter<__node_base_pointer>(
+          static_cast<__end_node_pointer>(__ptr_)));
       return *this;
     }
     _LIBCPP_INLINE_VISIBILITY
@@ -649,6 +856,10 @@ public:
 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_TYPE_VIS_ONLY __tree_const_iterator;
     template <class> friend class _LIBCPP_TYPE_VIS_ONLY __map_iterator;
@@ -658,21 +869,24 @@ private:
     template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multiset;
 };
 
-template <class _Tp, class _ConstNodePtr, class _DiffType>
+template <class _Tp, class _NodePtr, class _DiffType>
 class _LIBCPP_TYPE_VIS_ONLY __tree_const_iterator
 {
-    typedef _ConstNodePtr                                         __node_pointer;
-    typedef typename pointer_traits<__node_pointer>::element_type __node;
+    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;
 
-    __node_pointer __ptr_;
+    __iter_pointer __ptr_;
 
-    typedef pointer_traits<__node_pointer> __pointer_traits;
 public:
-    typedef bidirectional_iterator_tag       iterator_category;
-    typedef _Tp                              value_type;
-    typedef _DiffType                        difference_type;
-    typedef const value_type&                reference;
-    typedef typename __rebind_pointer<__node_pointer, const value_type>::type pointer;
+    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
@@ -681,26 +895,22 @@ public:
     {}
 
 private:
-    typedef typename remove_const<__node>::type  __non_const_node;
-    typedef typename __rebind_pointer<__node_pointer, __non_const_node>::type
-        __non_const_node_pointer;
-    typedef __tree_iterator<value_type, __non_const_node_pointer, difference_type>
-                                                 __non_const_iterator;
+    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 __ptr_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const
+        {return __get_np()->__value_;}
     _LIBCPP_INLINE_VISIBILITY pointer operator->() const
-        {return pointer_traits<pointer>::pointer_to(__ptr_->__value_);}
+        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
 
     _LIBCPP_INLINE_VISIBILITY
     __tree_const_iterator& operator++() {
-      typedef typename __rebind_pointer<__node_pointer, typename __node::base>::type
-        __node_base_pointer;
-      __ptr_ = static_cast<__node_pointer>(
-          __tree_next(static_cast<__node_base_pointer>(__ptr_)));
+      __ptr_ = static_cast<__iter_pointer>(
+          __tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
       return *this;
     }
 
@@ -710,10 +920,8 @@ public:
 
     _LIBCPP_INLINE_VISIBILITY
     __tree_const_iterator& operator--() {
-      typedef typename __rebind_pointer<__node_pointer, typename __node::base>::type
-        __node_base_pointer;
-      __ptr_ = static_cast<__node_pointer>(
-          __tree_prev(static_cast<__node_base_pointer>(__ptr_)));
+      __ptr_ = static_cast<__iter_pointer>(__tree_prev_iter<__node_base_pointer>(
+          static_cast<__end_node_pointer>(__ptr_)));
       return *this;
     }
 
@@ -732,12 +940,19 @@ 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_TYPE_VIS_ONLY map;
     template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multimap;
     template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY set;
     template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multiset;
     template <class> friend class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator;
+
 };
 
 template <class _Tp, class _Compare, class _Allocator>
@@ -747,48 +962,73 @@ 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;
 
-    typedef typename __alloc_traits::void_pointer  __void_pointer;
+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 __tree_node<value_type, __void_pointer> __node;
-    typedef __tree_node_base<__void_pointer>        __node_base;
     typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
-    typedef allocator_traits<__node_allocator>       __node_traits;
-    typedef typename __node_traits::pointer          __node_pointer;
-    typedef typename __node_traits::pointer          __node_const_pointer;
-    typedef typename __node_base::pointer            __node_base_pointer;
-    typedef typename __node_base::pointer            __node_base_const_pointer;
+    typedef allocator_traits<__node_allocator>         __node_traits;
+
 private:
-    typedef typename __node_base::base __end_node_t;
-    typedef typename __rebind_pointer<__node_pointer, __end_node_t>::type
-        __end_node_ptr;
-    typedef __end_node_ptr __end_node_const_ptr;
+    // 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.");
 
-    __node_pointer                                          __begin_node_;
+private:
+    __iter_pointer                                     __begin_node_;
     __compressed_pair<__end_node_t, __node_allocator>  __pair1_;
     __compressed_pair<size_type, value_compare>        __pair3_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __end_node() _NOEXCEPT
+    __iter_pointer __end_node() _NOEXCEPT
     {
-        return static_cast<__node_pointer>
-               (
-                   pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first())
-               );
+        return static_cast<__iter_pointer>(
+                pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first())
+        );
     }
     _LIBCPP_INLINE_VISIBILITY
-    __node_const_pointer __end_node() const _NOEXCEPT
+    __iter_pointer __end_node() const _NOEXCEPT
     {
-        return static_cast<__node_const_pointer>
-               (
-                   pointer_traits<__end_node_const_ptr>::pointer_to(const_cast<__end_node_t&>(__pair1_.first()))
-               );
+        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();}
@@ -797,9 +1037,9 @@ private:
     const __node_allocator& __node_alloc() const _NOEXCEPT
         {return __pair1_.second();}
     _LIBCPP_INLINE_VISIBILITY
-          __node_pointer& __begin_node() _NOEXCEPT {return __begin_node_;}
+          __iter_pointer& __begin_node() _NOEXCEPT {return __begin_node_;}
     _LIBCPP_INLINE_VISIBILITY
-    const __node_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;}
+    const __iter_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;}
 public:
     _LIBCPP_INLINE_VISIBILITY
     allocator_type __alloc() const _NOEXCEPT
@@ -816,12 +1056,14 @@ public:
     const value_compare& value_comp() const _NOEXCEPT
         {return __pair3_.second();}
 public:
+
     _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __root() _NOEXCEPT
-        {return static_cast<__node_pointer>      (__end_node()->__left_);}
-    _LIBCPP_INLINE_VISIBILITY
-    __node_const_pointer __root() const _NOEXCEPT
-        {return static_cast<__node_const_pointer>(__end_node()->__left_);}
+    __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;
@@ -877,45 +1119,195 @@ public:
 #endif
             );
 
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+#ifndef _LIBCPP_CXX03_LANG
+    template <class _Key, class ..._Args>
+    pair<iterator, bool>
+    __emplace_unique_key_args(_Key const&, _Args&&... __args);
+    template <class _Key, class ..._Args>
+    iterator
+    __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&&...);
+
     template <class... _Args>
-        pair<iterator, bool>
-        __emplace_unique(_Args&&... __args);
+    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
+
     template <class... _Args>
-        iterator
-        __emplace_multi(_Args&&... __args);
+    iterator __emplace_hint_unique_impl(const_iterator __p, _Args&&... __args);
 
     template <class... _Args>
-        iterator
-        __emplace_hint_unique(const_iterator __p, _Args&&... __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
-        __emplace_hint_multi(const_iterator __p, _Args&&... __args);
-#endif  // _LIBCPP_HAS_NO_VARIADICS
+    >::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));
+    }
 
-    template <class _Vp>
-        pair<iterator, bool> __insert_unique(_Vp&& __v);
-    template <class _Vp>
-        iterator __insert_unique(const_iterator __p, _Vp&& __v);
-    template <class _Vp>
-        iterator __insert_multi(_Vp&& __v);
-    template <class _Vp>
-        iterator __insert_multi(const_iterator __p, _Vp&& __v);
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    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)...);
+    }
 
-    pair<iterator, bool> __insert_unique(const value_type& __v);
-    iterator __insert_unique(const_iterator __p, const value_type& __v);
-    iterator __insert_multi(const value_type& __v);
-    iterator __insert_multi(const_iterator __p, const value_type& __v);
+    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));
+    }
 
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    pair<iterator, bool> __insert_unique(        value_type&& __v);
-    iterator __insert_unique(const_iterator __p, value_type&& __v);
-    iterator __insert_multi(                    value_type&& __v);
-    iterator __insert_multi(const_iterator __p, value_type&& __v);
+    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));
+    }
+
+    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));
+    }
+
+#else
+    template <class _Key, class _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool> __emplace_unique_key_args(_Key const&, _Args& __args);
+    template <class _Key, class _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    iterator __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&);
 #endif
 
+    _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);
+    }
+
+#ifdef _LIBCPP_CXX03_LANG
+    _LIBCPP_INLINE_VISIBILITY
+    iterator __insert_multi(const __container_value_type& __v);
+    _LIBCPP_INLINE_VISIBILITY
+    iterator __insert_multi(const_iterator __p, const __container_value_type& __v);
+#else
+    _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));
+    }
+
+    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));
+    }
+
+#endif // !_LIBCPP_CXX03_LANG
+
     pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
     iterator             __node_insert_unique(const_iterator __p,
                                               __node_pointer __nd);
@@ -930,7 +1322,7 @@ public:
     template <class _Key>
         size_type __erase_multi(const _Key& __k);
 
-    void __insert_node_at(__node_base_pointer __parent,
+    void __insert_node_at(__parent_pointer     __parent,
                           __node_base_pointer& __child,
                           __node_base_pointer __new_node);
 
@@ -951,15 +1343,15 @@ public:
     template <class _Key>
         iterator __lower_bound(const _Key& __v,
                                __node_pointer __root,
-                               __node_pointer __result);
+                               __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_const_pointer __root,
-                                     __node_const_pointer __result) const;
+                                     __node_pointer __root,
+                                     __iter_pointer __result) const;
     template <class _Key>
         _LIBCPP_INLINE_VISIBILITY
         iterator upper_bound(const _Key& __v)
@@ -967,15 +1359,15 @@ public:
     template <class _Key>
         iterator __upper_bound(const _Key& __v,
                                __node_pointer __root,
-                               __node_pointer __result);
+                               __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_const_pointer __root,
-                                     __node_const_pointer __result) const;
+                                     __node_pointer __root,
+                                     __iter_pointer __result) const;
     template <class _Key>
         pair<iterator, iterator>
         __equal_range_unique(const _Key& __k);
@@ -995,26 +1387,27 @@ public:
 
     __node_holder remove(const_iterator __p) _NOEXCEPT;
 private:
-    typename __node_base::pointer&
-        __find_leaf_low(typename __node_base::pointer& __parent, const value_type& __v);
-    typename __node_base::pointer&
-        __find_leaf_high(typename __node_base::pointer& __parent, const value_type& __v);
-    typename __node_base::pointer&
+    __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,
-                    typename __node_base::pointer& __parent, const value_type& __v);
+                    __parent_pointer& __parent, const key_type& __v);
     template <class _Key>
-        typename __node_base::pointer&
-        __find_equal(typename __node_base::pointer& __parent, const _Key& __v);
+    __node_base_pointer&
+        __find_equal(__parent_pointer& __parent, const _Key& __v);
     template <class _Key>
-        typename __node_base::pointer&
-        __find_equal(const_iterator __hint, typename __node_base::pointer& __parent,
+    __node_base_pointer&
+        __find_equal(const_iterator __hint, __parent_pointer& __parent,
+                     __node_base_pointer& __dummy,
                      const _Key& __v);
 
-#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+#ifndef _LIBCPP_CXX03_LANG
     template <class ..._Args>
-        __node_holder __construct_node(_Args&& ...__args);
-#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-        __node_holder __construct_node(const value_type& __v);
+    __node_holder __construct_node(_Args&& ...__args);
+#else
+    __node_holder __construct_node(const __container_value_type& __v);
 #endif
 
     void destroy(__node_pointer __nd) _NOEXCEPT;
@@ -1026,7 +1419,11 @@ private:
 
     _LIBCPP_INLINE_VISIBILITY
     void __copy_assign_alloc(const __tree& __t, true_type)
-        {__node_alloc() = __t.__node_alloc();}
+        {
+        if (__node_alloc() != __t.__node_alloc())
+        	clear();
+        __node_alloc() = __t.__node_alloc();
+        }
     _LIBCPP_INLINE_VISIBILITY
     void __copy_assign_alloc(const __tree& __t, false_type) {}
 
@@ -1069,7 +1466,7 @@ __tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp)
 
 template <class _Tp, class _Compare, class _Allocator>
 __tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a)
-    : __begin_node_(__node_pointer()),
+    : __begin_node_(__iter_pointer()),
       __pair1_(__node_allocator(__a)),
       __pair3_(0)
 {
@@ -1079,7 +1476,7 @@ __tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a)
 template <class _Tp, class _Compare, class _Allocator>
 __tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp,
                                            const allocator_type& __a)
-    : __begin_node_(__node_pointer()),
+    : __begin_node_(__iter_pointer()),
       __pair1_(__node_allocator(__a)),
       __pair3_(0, __comp)
 {
@@ -1091,7 +1488,7 @@ template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
 __tree<_Tp, _Compare, _Allocator>::__detach()
 {
-    __node_pointer __cache = __begin_node();
+    __node_pointer __cache = static_cast<__node_pointer>(__begin_node());
     __begin_node() = __end_node();
     __end_node()->__left_->__parent_ = nullptr;
     __end_node()->__left_ = nullptr;
@@ -1123,7 +1520,7 @@ __tree<_Tp, _Compare, _Allocator>::__detach(__node_pointer __cache)
         return static_cast<__node_pointer>(__tree_leaf(__cache->__right_));
     }
     // __cache is right child
-    __cache->__parent_->__right_ = nullptr;
+    __cache->__parent_unsafe()->__right_ = nullptr;
     __cache = static_cast<__node_pointer>(__cache->__parent_);
     if (__cache->__left_ == nullptr)
         return __cache;
@@ -1148,6 +1545,11 @@ template <class _InputIterator>
 void
 __tree<_Tp, _Compare, _Allocator>::__assign_unique(_InputIterator __first, _InputIterator __last)
 {
+    typedef iterator_traits<_InputIterator> _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");
+
     if (size() != 0)
     {
         __node_pointer __cache = __detach();
@@ -1188,6 +1590,12 @@ 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)
     {
         __node_pointer __cache = __detach();
@@ -1220,12 +1628,12 @@ __tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _Input
         }
     }
     for (; __first != __last; ++__first)
-        __insert_multi(*__first);
+        __insert_multi(_NodeTypes::__get_value(*__first));
 }
 
 template <class _Tp, class _Compare, class _Allocator>
 __tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t)
-    : __begin_node_(__node_pointer()),
+    : __begin_node_(__iter_pointer()),
       __pair1_(__node_traits::select_on_container_copy_construction(__t.__node_alloc())),
       __pair3_(0, __t.value_comp())
 {
@@ -1247,7 +1655,7 @@ __tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t)
         __begin_node() = __end_node();
     else
     {
-        __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
         __t.__begin_node() = __t.__end_node();
         __t.__end_node()->__left_ = nullptr;
         __t.size() = 0;
@@ -1267,7 +1675,7 @@ __tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __
         {
             __begin_node() = __t.__begin_node();
             __end_node()->__left_ = __t.__end_node()->__left_;
-            __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+            __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
             size() = __t.size();
             __t.__begin_node() = __t.__end_node();
             __t.__end_node()->__left_ = nullptr;
@@ -1295,7 +1703,7 @@ __tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type)
         __begin_node() = __end_node();
     else
     {
-        __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
         __t.__begin_node() = __t.__end_node();
         __t.__end_node()->__left_ = nullptr;
         __t.size() = 0;
@@ -1344,7 +1752,7 @@ __tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type)
             }
         }
         while (__t.size() != 0)
-            __insert_multi(__e, _VSTD::move(__t.remove(__t.begin())->__value_));
+            __insert_multi(__e, _NodeTypes::__move(__t.remove(__t.begin())->__value_));
     }
 }
 
@@ -1367,6 +1775,8 @@ __tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t)
 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());
 }
 
@@ -1379,7 +1789,7 @@ __tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT
         destroy(static_cast<__node_pointer>(__nd->__left_));
         destroy(static_cast<__node_pointer>(__nd->__right_));
         __node_allocator& __na = __node_alloc();
-        __node_traits::destroy(__na, _VSTD::addressof(__nd->__value_));
+        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__nd->__value_));
         __node_traits::deallocate(__na, __nd, 1);
     }
 }
@@ -1403,11 +1813,11 @@ __tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
     if (size() == 0)
         __begin_node() = __end_node();
     else
-        __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+        __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<__node_base_pointer>(__t.__end_node());
+        __t.__end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__t.__end_node());
 }
 
 template <class _Tp, class _Compare, class _Allocator>
@@ -1424,9 +1834,9 @@ __tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT
 // 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(typename __node_base::pointer& __parent,
-                                                   const value_type& __v)
+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)
@@ -1439,8 +1849,8 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf_low(typename __node_base::pointer
                     __nd = static_cast<__node_pointer>(__nd->__right_);
                 else
                 {
-                    __parent = static_cast<__node_base_pointer>(__nd);
-                    return __parent->__right_;
+                    __parent = static_cast<__parent_pointer>(__nd);
+                    return __nd->__right_;
                 }
             }
             else
@@ -1449,13 +1859,13 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf_low(typename __node_base::pointer
                     __nd = static_cast<__node_pointer>(__nd->__left_);
                 else
                 {
-                    __parent = static_cast<__node_base_pointer>(__nd);
+                    __parent = static_cast<__parent_pointer>(__nd);
                     return __parent->__left_;
                 }
             }
         }
     }
-    __parent = static_cast<__node_base_pointer>(__end_node());
+    __parent = static_cast<__parent_pointer>(__end_node());
     return __parent->__left_;
 }
 
@@ -1463,9 +1873,9 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf_low(typename __node_base::pointer
 // 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(typename __node_base::pointer& __parent,
-                                                    const value_type& __v)
+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)
@@ -1478,7 +1888,7 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf_high(typename __node_base::pointe
                     __nd = static_cast<__node_pointer>(__nd->__left_);
                 else
                 {
-                    __parent = static_cast<__node_base_pointer>(__nd);
+                    __parent = static_cast<__parent_pointer>(__nd);
                     return __parent->__left_;
                 }
             }
@@ -1488,13 +1898,13 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf_high(typename __node_base::pointe
                     __nd = static_cast<__node_pointer>(__nd->__right_);
                 else
                 {
-                    __parent = static_cast<__node_base_pointer>(__nd);
-                    return __parent->__right_;
+                    __parent = static_cast<__parent_pointer>(__nd);
+                    return __nd->__right_;
                 }
             }
         }
     }
-    __parent = static_cast<__node_base_pointer>(__end_node());
+    __parent = static_cast<__parent_pointer>(__end_node());
     return __parent->__left_;
 }
 
@@ -1505,10 +1915,10 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf_high(typename __node_base::pointe
 // 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&
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
 __tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
-                                               typename __node_base::pointer& __parent,
-                                               const value_type& __v)
+                                               __parent_pointer& __parent,
+                                               const key_type& __v)
 {
     if (__hint == end() || !value_comp()(*__hint, __v))  // check before
     {
@@ -1519,13 +1929,13 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
             // *prev(__hint) <= __v <= *__hint
             if (__hint.__ptr_->__left_ == nullptr)
             {
-                __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
+                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
                 return __parent->__left_;
             }
             else
             {
-                __parent = static_cast<__node_base_pointer>(__prior.__ptr_);
-                return __parent->__right_;
+                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
+                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
             }
         }
         // __v < *prev(__hint)
@@ -1541,43 +1951,44 @@ __tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
 // 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(typename __node_base::pointer& __parent,
+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)
+                if (__nd->__left_ != nullptr) {
+                    __nd_ptr = _VSTD::addressof(__nd->__left_);
                     __nd = static_cast<__node_pointer>(__nd->__left_);
-                else
-                {
-                    __parent = static_cast<__node_base_pointer>(__nd);
+                } else {
+                    __parent = static_cast<__parent_pointer>(__nd);
                     return __parent->__left_;
                 }
             }
             else if (value_comp()(__nd->__value_, __v))
             {
-                if (__nd->__right_ != nullptr)
+                if (__nd->__right_ != nullptr) {
+                    __nd_ptr = _VSTD::addressof(__nd->__right_);
                     __nd = static_cast<__node_pointer>(__nd->__right_);
-                else
-                {
-                    __parent = static_cast<__node_base_pointer>(__nd);
-                    return __parent->__right_;
+                } else {
+                    __parent = static_cast<__parent_pointer>(__nd);
+                    return __nd->__right_;
                 }
             }
             else
             {
-                __parent = static_cast<__node_base_pointer>(__nd);
-                return __parent;
+                __parent = static_cast<__parent_pointer>(__nd);
+                return *__nd_ptr;
             }
         }
     }
-    __parent = static_cast<__node_base_pointer>(__end_node());
+    __parent = static_cast<__parent_pointer>(__end_node());
     return __parent->__left_;
 }
 
@@ -1590,9 +2001,10 @@ __tree<_Tp, _Compare, _Allocator>::__find_equal(typename __node_base::pointer& _
 // 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&
+typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
 __tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
-                                                typename __node_base::pointer& __parent,
+                                                __parent_pointer& __parent,
+                                                __node_base_pointer& __dummy,
                                                 const _Key& __v)
 {
     if (__hint == end() || value_comp()(__v, *__hint))  // check before
@@ -1604,13 +2016,13 @@ __tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
             // *prev(__hint) < __v < *__hint
             if (__hint.__ptr_->__left_ == nullptr)
             {
-                __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
+                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
                 return __parent->__left_;
             }
             else
             {
-                __parent = static_cast<__node_base_pointer>(__prior.__ptr_);
-                return __parent->__right_;
+                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
+                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
             }
         }
         // __v <= *prev(__hint)
@@ -1623,14 +2035,14 @@ __tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
         if (__next == end() || value_comp()(__v, *__next))
         {
             // *__hint < __v < *_VSTD::next(__hint)
-            if (__hint.__ptr_->__right_ == nullptr)
+            if (__hint.__get_np()->__right_ == nullptr)
             {
-                __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
-                return __parent->__right_;
+                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
+                return static_cast<__node_base_pointer>(__hint.__ptr_)->__right_;
             }
             else
             {
-                __parent = static_cast<__node_base_pointer>(__next.__ptr_);
+                __parent = static_cast<__parent_pointer>(__next.__ptr_);
                 return __parent->__left_;
             }
         }
@@ -1638,48 +2050,115 @@ __tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
         return __find_equal(__parent, __v);
     }
     // else __v == *__hint
-    __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
-    return __parent;
+    __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(__node_base_pointer __parent,
+__tree<_Tp, _Compare, _Allocator>::__insert_node_at(__parent_pointer     __parent,
                                                     __node_base_pointer& __child,
-                                                    __node_base_pointer __new_node)
+                                                    __node_base_pointer  __new_node)
 {
     __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<__node_pointer>(__begin_node()->__left_);
+        __begin_node() = static_cast<__iter_pointer>(__begin_node()->__left_);
     __tree_balance_after_insert(__end_node()->__left_, __child);
     ++size();
 }
 
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#ifndef _LIBCPP_HAS_NO_VARIADICS
+#ifndef _LIBCPP_CXX03_LANG
+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)
+#else
+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)
+#endif
+{
+    __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)
+    {
+#ifndef _LIBCPP_CXX03_LANG
+        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+#else
+        __node_holder __h = __construct_node(__args);
+#endif
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+        __inserted = true;
+    }
+    return pair<iterator, bool>(iterator(__r), __inserted);
+}
+
+
+#ifndef _LIBCPP_CXX03_LANG
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key, class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args(
+    const_iterator __p, _Key const& __k, _Args&&... __args)
+#else
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key, class _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args(
+    const_iterator __p, _Key const& __k, _Args& __args)
+#endif
+{
+    __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);
+    if (__child == nullptr)
+    {
+#ifndef _LIBCPP_CXX03_LANG
+        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+#else
+        __node_holder __h = __construct_node(__args);
+#endif
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+    }
+    return iterator(__r);
+}
+
+
+#ifndef _LIBCPP_CXX03_LANG
 
 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, _VSTD::addressof(__h->__value_), _VSTD::forward<_Args>(__args)...);
+    __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(_Args&&... __args)
+__tree<_Tp, _Compare, _Allocator>::__emplace_unique_impl(_Args&&... __args)
 {
     __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __node_base_pointer __parent;
+    __parent_pointer __parent;
     __node_base_pointer& __child = __find_equal(__parent, __h->__value_);
     __node_pointer __r = static_cast<__node_pointer>(__child);
     bool __inserted = false;
@@ -1695,11 +2174,12 @@ __tree<_Tp, _Compare, _Allocator>::__emplace_unique(_Args&&... __args)
 template <class _Tp, class _Compare, class _Allocator>
 template <class... _Args>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique(const_iterator __p, _Args&&... __args)
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_impl(const_iterator __p, _Args&&... __args)
 {
     __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __h->__value_);
+    __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)
     {
@@ -1715,8 +2195,8 @@ typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args)
 {
     __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, __h->__value_);
+    __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()));
 }
@@ -1728,161 +2208,35 @@ __tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p,
                                                         _Args&&... __args)
 {
     __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, __h->__value_);
+    __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()));
 }
 
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Tp, class _Compare, class _Allocator>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__insert_unique(value_type&& __v)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<value_type>(__v));
-    pair<iterator, bool> __r = __node_insert_unique(__h.get());
-    if (__r.second)
-        __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_unique(const_iterator __p, value_type&& __v)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<value_type>(__v));
-    iterator __r = __node_insert_unique(__p, __h.get());
-    if (__r.__ptr_ == __h.get())
-        __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Vp>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__insert_unique(_Vp&& __v)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
-    pair<iterator, bool> __r = __node_insert_unique(__h.get());
-    if (__r.second)
-        __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Vp>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_unique(const_iterator __p, _Vp&& __v)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
-    iterator __r = __node_insert_unique(__p, __h.get());
-    if (__r.__ptr_ == __h.get())
-        __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(value_type&& __v)
-{
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, __v);
-    __node_holder __h = __construct_node(_VSTD::forward<value_type>(__v));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(__h.release());
-}
 
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, value_type&& __v)
-{
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, __v);
-    __node_holder __h = __construct_node(_VSTD::forward<value_type>(__v));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(__h.release());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Vp>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(_Vp&& __v)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, __h->__value_);
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(__h.release());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Vp>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, _Vp&& __v)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, __h->__value_);
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(__h.release());
-}
-
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#else  // _LIBCPP_CXX03_LANG
 
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::__node_holder
-__tree<_Tp, _Compare, _Allocator>::__construct_node(const value_type& __v)
+__tree<_Tp, _Compare, _Allocator>::__construct_node(const __container_value_type& __v)
 {
     __node_allocator& __na = __node_alloc();
     __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), __v);
+    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
     __h.get_deleter().__value_constructed = true;
     return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
 }
 
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp, class _Compare, class _Allocator>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__insert_unique(const value_type& __v)
-{
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __v);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __node_holder __h = __construct_node(__v);
-        __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>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_unique(const_iterator __p, const value_type& __v)
-{
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __v);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __node_holder __h = __construct_node(__v);
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-    }
-    return iterator(__r);
-}
+#endif  // _LIBCPP_CXX03_LANG
 
+#ifdef _LIBCPP_CXX03_LANG
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(const value_type& __v)
+__tree<_Tp, _Compare, _Allocator>::__insert_multi(const __container_value_type& __v)
 {
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, __v);
+    __parent_pointer __parent;
+    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__v));
     __node_holder __h = __construct_node(__v);
     __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
     return iterator(__h.release());
@@ -1890,20 +2244,21 @@ __tree<_Tp, _Compare, _Allocator>::__insert_multi(const value_type& __v)
 
 template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, const value_type& __v)
+__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, const __container_value_type& __v)
 {
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, __v);
+    __parent_pointer __parent;
+    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__v));
     __node_holder __h = __construct_node(__v);
     __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
     return iterator(__h.release());
 }
+#endif
 
 template <class _Tp, class _Compare, class _Allocator>
 pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
 __tree<_Tp, _Compare, _Allocator>::__node_insert_unique(__node_pointer __nd)
 {
-    __node_base_pointer __parent;
+    __parent_pointer __parent;
     __node_base_pointer& __child = __find_equal(__parent, __nd->__value_);
     __node_pointer __r = static_cast<__node_pointer>(__child);
     bool __inserted = false;
@@ -1921,7 +2276,8 @@ typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::__node_insert_unique(const_iterator __p,
                                                         __node_pointer __nd)
 {
-    __node_base_pointer __parent;
+    __parent_pointer __parent;
+    __node_base_pointer __dummy;
     __node_base_pointer& __child = __find_equal(__p, __parent, __nd->__value_);
     __node_pointer __r = static_cast<__node_pointer>(__child);
     if (__child == nullptr)
@@ -1936,8 +2292,8 @@ template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd)
 {
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, __nd->__value_);
+    __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);
 }
@@ -1947,8 +2303,8 @@ typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p,
                                                        __node_pointer __nd)
 {
-    __node_base_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, __nd->__value_);
+    __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);
 }
@@ -1957,16 +2313,17 @@ template <class _Tp, class _Compare, class _Allocator>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p)
 {
-    __node_pointer __np = __p.__ptr_;
-    iterator __r(__np);
+    __node_pointer __np = __p.__get_np();
+    iterator __r(__p.__ptr_);
     ++__r;
-    if (__begin_node() == __np)
+    if (__begin_node() == __p.__ptr_)
         __begin_node() = __r.__ptr_;
     --size();
     __node_allocator& __na = __node_alloc();
     __tree_remove(__end_node()->__left_,
                   static_cast<__node_base_pointer>(__np));
-    __node_traits::destroy(__na, const_cast<value_type*>(_VSTD::addressof(*__p)));
+    __node_traits::destroy(__na, _NodeTypes::__get_ptr(
+        const_cast<__node_value_type&>(*__p)));
     __node_traits::deallocate(__na, __np, 1);
     return __r;
 }
@@ -2031,17 +2388,15 @@ template <class _Key>
 typename __tree<_Tp, _Compare, _Allocator>::size_type
 __tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const
 {
-    __node_const_pointer __result = __end_node();
-    __node_const_pointer __rt = __root();
+    __node_pointer __rt = __root();
     while (__rt != nullptr)
     {
         if (value_comp()(__k, __rt->__value_))
         {
-            __result = __rt;
-            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+            __rt = static_cast<__node_pointer>(__rt->__left_);
         }
         else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+            __rt = static_cast<__node_pointer>(__rt->__right_);
         else
             return 1;
     }
@@ -2053,21 +2408,21 @@ template <class _Key>
 typename __tree<_Tp, _Compare, _Allocator>::size_type
 __tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const
 {
-    __node_const_pointer __result = __end_node();
-    __node_const_pointer __rt = __root();
+    __iter_pointer __result = __end_node();
+    __node_pointer __rt = __root();
     while (__rt != nullptr)
     {
         if (value_comp()(__k, __rt->__value_))
         {
-            __result = __rt;
-            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+            __result = static_cast<__iter_pointer>(__rt);
+            __rt = static_cast<__node_pointer>(__rt->__left_);
         }
         else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+            __rt = static_cast<__node_pointer>(__rt->__right_);
         else
             return _VSTD::distance(
-                __lower_bound(__k, static_cast<__node_const_pointer>(__rt->__left_), __rt),
-                __upper_bound(__k, static_cast<__node_const_pointer>(__rt->__right_), __result)
+                __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;
@@ -2078,13 +2433,13 @@ template <class _Key>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
                                                  __node_pointer __root,
-                                                 __node_pointer __result)
+                                                 __iter_pointer __result)
 {
     while (__root != nullptr)
     {
         if (!value_comp()(__root->__value_, __v))
         {
-            __result = __root;
+            __result = static_cast<__iter_pointer>(__root);
             __root = static_cast<__node_pointer>(__root->__left_);
         }
         else
@@ -2097,18 +2452,18 @@ 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_const_pointer __root,
-                                                 __node_const_pointer __result) const
+                                                 __node_pointer __root,
+                                                 __iter_pointer __result) const
 {
     while (__root != nullptr)
     {
         if (!value_comp()(__root->__value_, __v))
         {
-            __result = __root;
-            __root = static_cast<__node_const_pointer>(__root->__left_);
+            __result = static_cast<__iter_pointer>(__root);
+            __root = static_cast<__node_pointer>(__root->__left_);
         }
         else
-            __root = static_cast<__node_const_pointer>(__root->__right_);
+            __root = static_cast<__node_pointer>(__root->__right_);
     }
     return const_iterator(__result);
 }
@@ -2118,13 +2473,13 @@ template <class _Key>
 typename __tree<_Tp, _Compare, _Allocator>::iterator
 __tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
                                                  __node_pointer __root,
-                                                 __node_pointer __result)
+                                                 __iter_pointer __result)
 {
     while (__root != nullptr)
     {
         if (value_comp()(__v, __root->__value_))
         {
-            __result = __root;
+            __result = static_cast<__iter_pointer>(__root);
             __root = static_cast<__node_pointer>(__root->__left_);
         }
         else
@@ -2137,18 +2492,18 @@ 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_const_pointer __root,
-                                                 __node_const_pointer __result) const
+                                                 __node_pointer __root,
+                                                 __iter_pointer __result) const
 {
     while (__root != nullptr)
     {
         if (value_comp()(__v, __root->__value_))
         {
-            __result = __root;
-            __root = static_cast<__node_const_pointer>(__root->__left_);
+            __result = static_cast<__iter_pointer>(__root);
+            __root = static_cast<__node_pointer>(__root->__left_);
         }
         else
-            __root = static_cast<__node_const_pointer>(__root->__right_);
+            __root = static_cast<__node_pointer>(__root->__right_);
     }
     return const_iterator(__result);
 }
@@ -2160,13 +2515,13 @@ pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
 __tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k)
 {
     typedef pair<iterator, iterator> _Pp;
-    __node_pointer __result = __end_node();
+    __iter_pointer __result = __end_node();
     __node_pointer __rt = __root();
     while (__rt != nullptr)
     {
         if (value_comp()(__k, __rt->__value_))
         {
-            __result = __rt;
+            __result = static_cast<__iter_pointer>(__rt);
             __rt = static_cast<__node_pointer>(__rt->__left_);
         }
         else if (value_comp()(__rt->__value_, __k))
@@ -2175,7 +2530,7 @@ __tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k)
             return _Pp(iterator(__rt),
                       iterator(
                           __rt->__right_ != nullptr ?
-                              static_cast<__node_pointer>(__tree_min(__rt->__right_))
+                              static_cast<__iter_pointer>(__tree_min(__rt->__right_))
                             : __result));
     }
     return _Pp(iterator(__result), iterator(__result));
@@ -2188,22 +2543,22 @@ pair<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;
-    __node_const_pointer __result = __end_node();
-    __node_const_pointer __rt = __root();
+    __iter_pointer __result = __end_node();
+    __node_pointer __rt = __root();
     while (__rt != nullptr)
     {
         if (value_comp()(__k, __rt->__value_))
         {
-            __result = __rt;
-            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+            __result = static_cast<__iter_pointer>(__rt);
+            __rt = static_cast<__node_pointer>(__rt->__left_);
         }
         else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+            __rt = static_cast<__node_pointer>(__rt->__right_);
         else
             return _Pp(const_iterator(__rt),
                       const_iterator(
                           __rt->__right_ != nullptr ?
-                              static_cast<__node_const_pointer>(__tree_min(__rt->__right_))
+                              static_cast<__iter_pointer>(__tree_min(__rt->__right_))
                             : __result));
     }
     return _Pp(const_iterator(__result), const_iterator(__result));
@@ -2216,19 +2571,19 @@ pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
 __tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k)
 {
     typedef pair<iterator, iterator> _Pp;
-    __node_pointer __result = __end_node();
+    __iter_pointer __result = __end_node();
     __node_pointer __rt = __root();
     while (__rt != nullptr)
     {
         if (value_comp()(__k, __rt->__value_))
         {
-            __result = __rt;
+            __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_), __rt),
+            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));
@@ -2241,20 +2596,20 @@ pair<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;
-    __node_const_pointer __result = __end_node();
-    __node_const_pointer __rt = __root();
+    __iter_pointer __result = __end_node();
+    __node_pointer __rt = __root();
     while (__rt != nullptr)
     {
         if (value_comp()(__k, __rt->__value_))
         {
-            __result = __rt;
-            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+            __result = static_cast<__iter_pointer>(__rt);
+            __rt = static_cast<__node_pointer>(__rt->__left_);
         }
         else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+            __rt = static_cast<__node_pointer>(__rt->__right_);
         else
-            return _Pp(__lower_bound(__k, static_cast<__node_const_pointer>(__rt->__left_), __rt),
-                      __upper_bound(__k, static_cast<__node_const_pointer>(__rt->__right_), __result));
+            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));
 }
@@ -2263,13 +2618,13 @@ 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.__ptr_;
-    if (__begin_node() == __np)
+    __node_pointer __np = __p.__get_np();
+    if (__begin_node() == __p.__ptr_)
     {
         if (__np->__right_ != nullptr)
-            __begin_node() = static_cast<__node_pointer>(__np->__right_);
+            __begin_node() = static_cast<__iter_pointer>(__np->__right_);
         else
-            __begin_node() = static_cast<__node_pointer>(__np->__parent_);
+            __begin_node() = static_cast<__iter_pointer>(__np->__parent_);
     }
     --size();
     __tree_remove(__end_node()->__left_,