diff --git a/libstdc++-v3/include/bits/stl_map.h b/libstdc++-v3/include/bits/stl_map.h
index 773b72e..25ab25d 100644
--- a/libstdc++-v3/include/bits/stl_map.h
+++ b/libstdc++-v3/include/bits/stl_map.h
@@ -232,7 +232,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       /// Allocator-extended default constructor.
       explicit
       map(const allocator_type& __a)
-      : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
+      : _M_t(_Pair_alloc_type(__a)) { }
 
       /// Allocator-extended copy constructor.
       map(const map& __m, const allocator_type& __a)
@@ -246,14 +246,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
       /// Allocator-extended initialier-list constructor.
       map(initializer_list<value_type> __l, const allocator_type& __a)
-      : _M_t(_Compare(), _Pair_alloc_type(__a))
+      : _M_t(_Pair_alloc_type(__a))
       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
 
       /// Allocator-extended range constructor.
       template<typename _InputIterator>
 	map(_InputIterator __first, _InputIterator __last,
 	    const allocator_type& __a)
-	: _M_t(_Compare(), _Pair_alloc_type(__a))
+	: _M_t(_Pair_alloc_type(__a))
 	{ _M_t._M_insert_unique(__first, __last); }
 #endif
 
@@ -269,7 +269,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
        */
       template<typename _InputIterator>
 	map(_InputIterator __first, _InputIterator __last)
-	: _M_t()
 	{ _M_t._M_insert_unique(__first, __last); }
 
       /**
diff --git a/libstdc++-v3/include/bits/stl_multimap.h b/libstdc++-v3/include/bits/stl_multimap.h
index 9845c01..fcfea88 100644
--- a/libstdc++-v3/include/bits/stl_multimap.h
+++ b/libstdc++-v3/include/bits/stl_multimap.h
@@ -229,7 +229,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       /// Allocator-extended default constructor.
       explicit
       multimap(const allocator_type& __a)
-      : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
+      : _M_t(_Pair_alloc_type(__a)) { }
 
       /// Allocator-extended copy constructor.
       multimap(const multimap& __m, const allocator_type& __a)
@@ -243,14 +243,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
       /// Allocator-extended initialier-list constructor.
       multimap(initializer_list<value_type> __l, const allocator_type& __a)
-      : _M_t(_Compare(), _Pair_alloc_type(__a))
+      : _M_t(_Pair_alloc_type(__a))
       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
 
       /// Allocator-extended range constructor.
       template<typename _InputIterator>
 	multimap(_InputIterator __first, _InputIterator __last,
 		 const allocator_type& __a)
-	: _M_t(_Compare(), _Pair_alloc_type(__a))
+	: _M_t(_Pair_alloc_type(__a))
 	{ _M_t._M_insert_equal(__first, __last); }
 #endif
 
@@ -265,7 +265,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
        */
       template<typename _InputIterator>
 	multimap(_InputIterator __first, _InputIterator __last)
-	: _M_t()
 	{ _M_t._M_insert_equal(__first, __last); }
 
       /**
diff --git a/libstdc++-v3/include/bits/stl_multiset.h b/libstdc++-v3/include/bits/stl_multiset.h
index 38159ab..1155e55 100644
--- a/libstdc++-v3/include/bits/stl_multiset.h
+++ b/libstdc++-v3/include/bits/stl_multiset.h
@@ -185,7 +185,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
        */
       template<typename _InputIterator>
 	multiset(_InputIterator __first, _InputIterator __last)
-	: _M_t()
 	{ _M_t._M_insert_equal(__first, __last); }
 
       /**
@@ -245,7 +244,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       /// Allocator-extended default constructor.
       explicit
       multiset(const allocator_type& __a)
-      : _M_t(_Compare(), _Key_alloc_type(__a)) { }
+      : _M_t(_Key_alloc_type(__a)) { }
 
       /// Allocator-extended copy constructor.
       multiset(const multiset& __m, const allocator_type& __a)
@@ -259,14 +258,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
       /// Allocator-extended initialier-list constructor.
       multiset(initializer_list<value_type> __l, const allocator_type& __a)
-      : _M_t(_Compare(), _Key_alloc_type(__a))
+      : _M_t(_Key_alloc_type(__a))
       { _M_t._M_insert_equal(__l.begin(), __l.end()); }
 
       /// Allocator-extended range constructor.
       template<typename _InputIterator>
 	multiset(_InputIterator __first, _InputIterator __last,
 		 const allocator_type& __a)
-	: _M_t(_Compare(), _Key_alloc_type(__a))
+	: _M_t(_Key_alloc_type(__a))
 	{ _M_t._M_insert_equal(__first, __last); }
 
       /**
diff --git a/libstdc++-v3/include/bits/stl_set.h b/libstdc++-v3/include/bits/stl_set.h
index 913af9d..1dcec9f 100644
--- a/libstdc++-v3/include/bits/stl_set.h
+++ b/libstdc++-v3/include/bits/stl_set.h
@@ -189,7 +189,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
        */
       template<typename _InputIterator>
 	set(_InputIterator __first, _InputIterator __last)
-	: _M_t()
 	{ _M_t._M_insert_unique(__first, __last); }
 
       /**
@@ -249,7 +248,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       /// Allocator-extended default constructor.
       explicit
       set(const allocator_type& __a)
-      : _M_t(_Compare(), _Key_alloc_type(__a)) { }
+      : _M_t(_Key_alloc_type(__a)) { }
 
       /// Allocator-extended copy constructor.
       set(const set& __x, const allocator_type& __a)
@@ -263,14 +262,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
       /// Allocator-extended initialier-list constructor.
       set(initializer_list<value_type> __l, const allocator_type& __a)
-      : _M_t(_Compare(), _Key_alloc_type(__a))
+      : _M_t(_Key_alloc_type(__a))
       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
 
       /// Allocator-extended range constructor.
       template<typename _InputIterator>
 	set(_InputIterator __first, _InputIterator __last,
 	    const allocator_type& __a)
-	: _M_t(_Compare(), _Key_alloc_type(__a))
+	: _M_t(_Key_alloc_type(__a))
 	{ _M_t._M_insert_unique(__first, __last); }
 
       /**
diff --git a/libstdc++-v3/include/bits/stl_tree.h b/libstdc++-v3/include/bits/stl_tree.h
index c4f08d2..a4bbee4 100644
--- a/libstdc++-v3/include/bits/stl_tree.h
+++ b/libstdc++-v3/include/bits/stl_tree.h
@@ -753,6 +753,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #else
 	  _Rb_tree_impl(_Rb_tree_impl&&) = default;
 
+	  explicit
+	  _Rb_tree_impl(_Node_allocator&& __a)
+	  : _Node_allocator(std::move(__a))
+	  { }
+
 	  _Rb_tree_impl(_Rb_tree_impl&& __x, _Node_allocator&& __a)
 	  : _Node_allocator(std::move(__a)),
 	    _Base_key_compare(std::move(__x)),
@@ -986,7 +991,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #if __cplusplus >= 201103L
       _Rb_tree(const allocator_type& __a)
-      : _M_impl(_Compare(), _Node_allocator(__a))
+      : _M_impl(_Node_allocator(__a))
       { }
 
       _Rb_tree(const _Rb_tree& __x, const allocator_type& __a)