Index: include/memory
===================================================================
--- include/memory
+++ include/memory
@@ -1510,6 +1510,8 @@
 template <class _Alloc>
 struct _LIBCPP_TEMPLATE_VIS allocator_traits
 {
+    typedef _Alloc __is_uncustomized;
+
     typedef _Alloc                              allocator_type;
     typedef typename allocator_type::value_type value_type;
 
@@ -1609,28 +1611,23 @@
         _LIBCPP_INLINE_VISIBILITY
         static
         void
-        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
+        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2, false_type)
         {
             for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
                 construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
         }
 
-    template <class _Tp>
+    template <class _Ptr>
         _LIBCPP_INLINE_VISIBILITY
         static
-        typename enable_if
-        <
-            (__is_default_allocator<allocator_type>::value
-                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
-             is_trivially_move_constructible<_Tp>::value,
-            void
-        >::type
-        __construct_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
+        void
+        __construct_forward(allocator_type&, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2, true_type)
         {
+            typedef typename iterator_traits<_Ptr>::value_type _Tp;
+            typedef typename remove_const<_Tp>::type _Vp;
             ptrdiff_t _Np = __end1 - __begin1;
-            if (_Np > 0)
-            {
-                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
+            if (_Np > 0) {
+                _VSTD::memcpy(const_cast<_Vp*>(_VSTD::__to_raw_pointer(__begin2)), _VSTD::__to_raw_pointer(__begin1), _Np * sizeof(_Tp));
                 __begin2 += _Np;
             }
         }
@@ -1672,7 +1669,7 @@
         _LIBCPP_INLINE_VISIBILITY
         static
         void
-        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
+        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2, false_type)
         {
             while (__end1 != __begin1)
             {
@@ -1681,22 +1678,19 @@
             }
         }
 
-    template <class _Tp>
+    template <class _Ptr>
         _LIBCPP_INLINE_VISIBILITY
         static
-        typename enable_if
-        <
-            (__is_default_allocator<allocator_type>::value
-                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
-             is_trivially_move_constructible<_Tp>::value,
-            void
-        >::type
-        __construct_backward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
+        void
+        __construct_backward(allocator_type&, _Ptr __begin1, _Ptr __end1, _Ptr& __end2, true_type)
         {
+            typedef typename iterator_traits<_Ptr>::value_type _Tp;
+            typedef typename remove_const<_Tp>::type _Vp;
             ptrdiff_t _Np = __end1 - __begin1;
             __end2 -= _Np;
-            if (_Np > 0)
-                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
+            if (_Np > 0) {
+                _VSTD::memcpy(const_cast<_Vp*>(_VSTD::__to_raw_pointer(__end2)), _VSTD::__to_raw_pointer(__begin1), _Np * sizeof(_Tp));
+            }
         }
 
 private:
@@ -5757,6 +5751,31 @@
   }
 };
 
+// __has_trivial_construct, __has_trivial_destroy
+
+template <class _Alloc, class = _Alloc>
+struct __has_customized_allocator_traits : true_type {};
+
+template <class _Alloc>
+struct __has_customized_allocator_traits<_Alloc, typename allocator_traits<_Alloc>::__is_uncustomized> : false_type {};
+
+template <class _Alloc>
+struct __is_exactly_std_allocator : false_type {};
+
+template <class _Tp>
+struct __is_exactly_std_allocator<allocator<_Tp> > : true_type {};
+
+template <class _Alloc, class _Tp, class... _Args>
+struct __has_trivial_construct : integral_constant<bool,
+    (__is_exactly_std_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Args...>::value) &&
+    !__has_customized_allocator_traits<_Alloc>::value
+> {};
+
+template <class _Alloc, class _Tp>
+struct __has_trivial_destroy : integral_constant<bool,
+    (__is_exactly_std_allocator<_Alloc>::value || !__has_destroy<_Alloc, _Tp*>::value) &&
+    !__has_customized_allocator_traits<_Alloc>::value
+> {};
 
 _LIBCPP_END_NAMESPACE_STD
 
Index: include/vector
===================================================================
--- include/vector
+++ include/vector
@@ -472,6 +472,33 @@
     }
 }
 
+template<class _Tp, class _Allocator>
+struct __vector_copy_via_memcpy : integral_constant<bool,
+    is_trivially_move_constructible<_Tp>::value &&
+    __has_trivial_construct<_Allocator, _Tp,
+#ifndef _LIBCPP_CXX03_LANG
+        _Tp&&
+#else
+        const _Tp&
+#endif
+    >::value &&
+    !is_volatile<_Tp>::value
+> {};
+
+template<class _Tp, class _Allocator>
+struct __vector_relocate_via_memcpy : integral_constant<bool,
+    __libcpp_is_trivially_relocatable<_Tp>::value &&
+    __has_trivial_construct<_Allocator, _Tp,
+#ifndef _LIBCPP_CXX03_LANG
+        _Tp&&
+#else
+        const _Tp&
+#endif
+    >::value &&
+    __has_trivial_destroy<_Allocator, _Tp>::value &&
+    !is_volatile<_Tp>::value
+> {};
+
 template <class _Tp, class _Allocator /* = allocator<_Tp> */>
 class _LIBCPP_TEMPLATE_VIS
       _LIBCPP_TRIVIALLY_RELOCATABLE_IF((__vector_base<_Tp, _Allocator>::__allow_trivial_relocation::value))
@@ -956,12 +983,21 @@
 void
 vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v)
 {
+    typedef integral_constant<bool,
+        __vector_copy_via_memcpy<_Tp, _Allocator>::value ||
+        __vector_relocate_via_memcpy<_Tp, _Allocator>::value
+    > __copy_via_memcpy;
+    typedef integral_constant<bool,
+        __vector_relocate_via_memcpy<_Tp, _Allocator>::value
+    > __destroy_via_noop;
+
     __annotate_delete();
-    __alloc_traits::__construct_backward(this->__alloc(), this->__begin_, this->__end_, __v.__begin_);
+    __alloc_traits::__construct_backward(this->__alloc(), this->__begin_, this->__end_, __v.__begin_, __copy_via_memcpy());
     _VSTD::swap(this->__begin_, __v.__begin_);
     _VSTD::swap(this->__end_, __v.__end_);
     _VSTD::swap(this->__end_cap(), __v.__end_cap());
     __v.__first_ = __v.__begin_;
+    __v.__destruct_at_end(__v.__begin_, __destroy_via_noop());
     __annotate_new(size());
     __invalidate_all_iterators();
 }
@@ -970,14 +1006,23 @@
 typename vector<_Tp, _Allocator>::pointer
 vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p)
 {
+    typedef integral_constant<bool,
+        __vector_copy_via_memcpy<_Tp, _Allocator>::value ||
+        __vector_relocate_via_memcpy<_Tp, _Allocator>::value
+    > __copy_via_memcpy;
+    typedef integral_constant<bool,
+        __vector_relocate_via_memcpy<_Tp, _Allocator>::value
+    > __destroy_via_noop;
+
     __annotate_delete();
     pointer __r = __v.__begin_;
-    __alloc_traits::__construct_backward(this->__alloc(), this->__begin_, __p, __v.__begin_);
-    __alloc_traits::__construct_forward(this->__alloc(), __p, this->__end_, __v.__end_);
+    __alloc_traits::__construct_backward(this->__alloc(), this->__begin_, __p, __v.__begin_, __copy_via_memcpy());
+    __alloc_traits::__construct_forward(this->__alloc(), __p, this->__end_, __v.__end_, __copy_via_memcpy());
     _VSTD::swap(this->__begin_, __v.__begin_);
     _VSTD::swap(this->__end_, __v.__end_);
     _VSTD::swap(this->__end_cap(), __v.__end_cap());
     __v.__first_ = __v.__begin_;
+    __v.__destruct_at_end(__v.__begin_, __destroy_via_noop());
     __annotate_new(size());
     __invalidate_all_iterators();
     return __r;
@@ -1719,7 +1764,16 @@
         "vector::erase(iterator) called with a non-dereferenceable iterator");
     difference_type __ps = __position - cbegin();
     pointer __p = this->__begin_ + __ps;
-    this->__destruct_at_end(_VSTD::move(__p + 1, this->__end_, __p));
+    _Tp *__rawp = _VSTD::__to_raw_pointer(__p);
+    if (__vector_relocate_via_memcpy<_Tp, _Allocator>::value) {
+        __alloc_traits::destroy(this->__alloc(), __rawp);
+        --this->__end_;
+        if (__p != this->__end_) {
+            _VSTD::memmove(__rawp, __rawp + 1, this->__end_ - __p);
+        }
+    } else {
+        this->__destruct_at_end(_VSTD::move(__p + 1, this->__end_, __p));
+    }
     this->__invalidate_iterators_past(__p-1);
     iterator __r = __make_iter(__p);
     return __r;
@@ -1751,6 +1805,16 @@
 void
 vector<_Tp, _Allocator>::__move_range(pointer __from_s, pointer __from_e, pointer __to)
 {
+#ifndef _LIBCPP_NO_TR_INSERT_OPTIMIZATION
+    if (__vector_relocate_via_memcpy<_Tp, _Allocator>::value && (__to == __from_s + 1) && (__from_e - __from_s >= 2)) {
+        _VSTD::memmove(_VSTD::__to_raw_pointer(__to + 1), _VSTD::__to_raw_pointer(__to), ((__from_e - __from_s) - 1) * sizeof(_Tp));
+        ++this->__end_;
+        __alloc_traits::construct(this->__alloc(),
+                                  _VSTD::__to_raw_pointer(__to),
+                                  _VSTD::move(*__from_s));
+        return;
+    }
+#endif
     pointer __old_last = this->__end_;
     difference_type __n = __old_last - __to;
     {