diff --git a/libcxx/include/list b/libcxx/include/list
--- a/libcxx/include/list
+++ b/libcxx/include/list
@@ -270,11 +270,21 @@
 struct __list_node
     : public __list_node_base<_Tp, _VoidPtr>
 {
-    _Tp __value_;
+
+#ifndef _LIBCPP_CXX03_LANG
+    union {
+      _Tp __value_;
+    };
+#else
+    typename aligned_storage<sizeof(_Tp)>::type __value_;
+#endif
 
     typedef __list_node_base<_Tp, _VoidPtr> __base;
     typedef typename __base::__link_pointer __link_pointer;
 
+    _LIBCPP_INLINE_VISIBILITY
+    __list_node() {}
+
     _LIBCPP_INLINE_VISIBILITY
     __link_pointer __as_link() {
         return static_cast<__link_pointer>(__base::__self());
@@ -360,7 +370,11 @@
         _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
                        "Attempted to dereference a non-dereferenceable list::iterator");
 #endif
+#ifndef _LIBCPP_CXX03_LANG
         return __ptr_->__as_node()->__value_;
+#else
+        return *reinterpret_cast<value_type*>(&__ptr_->__as_node()->__value_);
+#endif
     }
     _LIBCPP_INLINE_VISIBILITY
     pointer operator->() const
@@ -487,7 +501,12 @@
         _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
                        "Attempted to dereference a non-dereferenceable list::const_iterator");
 #endif
+
+#ifndef _LIBCPP_CXX03_LANG
         return __ptr_->__as_node()->__value_;
+#else
+        return *reinterpret_cast<value_type*>(&__ptr_->__as_node()->__value_);
+#endif
     }
     _LIBCPP_INLINE_VISIBILITY
     pointer operator->() const
@@ -496,7 +515,13 @@
         _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
                        "Attempted to dereference a non-dereferenceable list::const_iterator");
 #endif
+
+#ifndef _LIBCPP_CXX03_LANG
         return pointer_traits<pointer>::pointer_to(__ptr_->__as_node()->__value_);
+#else
+        return pointer_traits<pointer>::pointer_to(
+            *reinterpret_cast<value_type*>(&__ptr_->__as_node()->__value_));
+#endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
@@ -761,7 +786,12 @@
         {
             __node_pointer __np = __f->__as_node();
             __f = __f->__next_;
+#ifndef _LIBCPP_CXX03_LANG
             __node_alloc_traits::destroy(__na, _VSTD::addressof(__np->__value_));
+#else
+            __node_alloc_traits::destroy(__na, _VSTD::addressof(
+                *reinterpret_cast<value_type*>(&__np->__value_)));
+#endif
             __node_alloc_traits::deallocate(__na, __np, 1);
         }
         __invalidate_all_iterators();
@@ -978,25 +1008,41 @@
     reference front()
     {
         _LIBCPP_ASSERT(!empty(), "list::front called on empty list");
+#ifndef _LIBCPP_CXX03_LANG
         return base::__end_.__next_->__as_node()->__value_;
+#else
+        return *reinterpret_cast<value_type*>(&base::__end_.__next_->__as_node()->__value_);
+#endif
     }
     _LIBCPP_INLINE_VISIBILITY
     const_reference front() const
     {
         _LIBCPP_ASSERT(!empty(), "list::front called on empty list");
+#ifndef _LIBCPP_CXX03_LANG
         return base::__end_.__next_->__as_node()->__value_;
+#else
+        return *reinterpret_cast<value_type*>(&base::__end_.__next_->__as_node()->__value_);
+#endif
     }
     _LIBCPP_INLINE_VISIBILITY
     reference back()
     {
         _LIBCPP_ASSERT(!empty(), "list::back called on empty list");
+#ifndef _LIBCPP_CXX03_LANG
         return base::__end_.__prev_->__as_node()->__value_;
+#else
+        return *reinterpret_cast<value_type*>(&base::__end_.__prev_->__as_node()->__value_);
+#endif
     }
     _LIBCPP_INLINE_VISIBILITY
     const_reference back() const
     {
         _LIBCPP_ASSERT(!empty(), "list::back called on empty list");
+#ifndef _LIBCPP_CXX03_LANG
         return base::__end_.__prev_->__as_node()->__value_;
+#else
+        return *reinterpret_cast<value_type*>(&base::__end_.__prev_->__as_node()->__value_);
+#endif
     }
 
 #ifndef _LIBCPP_CXX03_LANG
@@ -1113,6 +1159,7 @@
     _LIBCPP_INLINE_VISIBILITY
     __hold_pointer __allocate_node(__node_allocator& __na) {
       __node_pointer __p = __node_alloc_traits::allocate(__na, 1);
+      ::new ((void*)_VSTD::addressof(*__p)) __node();
       __p->__prev_ = nullptr;
       return __hold_pointer(__p, __node_destructor(__na, 1));
     }
@@ -1456,7 +1503,12 @@
 #endif
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
     __link_nodes(__p.__ptr_, __hold->__as_link(), __hold->__as_link());
     ++base::__sz();
 #if _LIBCPP_DEBUG_LEVEL == 2
@@ -1483,7 +1535,13 @@
         size_type __ds = 0;
         __node_allocator& __na = base::__node_alloc();
         __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
         __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+        __node_alloc_traits::construct(__na, _VSTD::addressof(
+            *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
+
         ++__ds;
 #if _LIBCPP_DEBUG_LEVEL == 2
         __r = iterator(__hold->__as_link(), this);
@@ -1499,7 +1557,12 @@
             for (--__n; __n != 0; --__n, ++__e, ++__ds)
             {
                 __hold.reset(__node_alloc_traits::allocate(__na, 1));
+#ifndef _LIBCPP_CXX03_LANG
                 __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+                __node_alloc_traits::construct(__na, _VSTD::addressof(
+                    *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
                 __e.__ptr_->__next_ = __hold->__as_link();
                 __hold->__prev_ = __e.__ptr_;
                 __hold.release();
@@ -1549,7 +1612,12 @@
         size_type __ds = 0;
         __node_allocator& __na = base::__node_alloc();
         __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
         __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), *__f);
+#else
+        __node_alloc_traits::construct(__na, _VSTD::addressof(
+            *reinterpret_cast<value_type*>(&__hold->__value_)), *__f);
+#endif
         ++__ds;
 #if _LIBCPP_DEBUG_LEVEL == 2
         __r = iterator(__hold.get()->__as_link(), this);
@@ -1565,7 +1633,12 @@
             for (++__f; __f != __l; ++__f, (void) ++__e, (void) ++__ds)
             {
                 __hold.reset(__node_alloc_traits::allocate(__na, 1));
+#ifndef _LIBCPP_CXX03_LANG
                 __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), *__f);
+#else
+                __node_alloc_traits::construct(__na, _VSTD::addressof(
+                    *reinterpret_cast<value_type*>(&__hold->__value_)), *__f);
+#endif
                 __e.__ptr_->__next_ = __hold.get()->__as_link();
                 __hold->__prev_ = __e.__ptr_;
                 __hold.release();
@@ -1602,7 +1675,13 @@
 {
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
+
     __link_pointer __nl = __hold->__as_link();
     __link_nodes_at_front(__nl, __nl);
     ++base::__sz();
@@ -1615,7 +1694,12 @@
 {
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
     __link_nodes_at_back(__hold.get()->__as_link(), __hold.get()->__as_link());
     ++base::__sz();
     __hold.release();
@@ -1629,7 +1713,12 @@
 {
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_), _VSTD::move(__x));
+#endif
     __link_nodes_at_front(__hold.get()->__as_link(), __hold.get()->__as_link());
     ++base::__sz();
     __hold.release();
@@ -1641,7 +1730,12 @@
 {
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_), __x);
+#endif
     __link_nodes_at_back(__hold.get()->__as_link(), __hold.get()->__as_link());
     ++base::__sz();
     __hold.release();
@@ -1658,11 +1752,21 @@
 {
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_), _VSTD::forward<_Args>(__args)...);
+#endif
     __link_nodes_at_front(__hold.get()->__as_link(), __hold.get()->__as_link());
     ++base::__sz();
 #if _LIBCPP_STD_VER > 14
+#ifndef _LIBCPP_CXX03_LANG
     return __hold.release()->__value_;
+#else
+    return *reinterpret_cast<value_type*>(&__hold.release()->__value_);
+#endif
+
 #else
     __hold.release();
 #endif
@@ -1679,12 +1783,21 @@
 {
     __node_allocator& __na = base::__node_alloc();
     __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
     __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
+#else
+    __node_alloc_traits::construct(__na, _VSTD::addressof(
+        *reinterpret_cast<value_type*>(&__hold->__value_), _VSTD::forward<_Args>(__args)...);
+#endif
     __link_pointer __nl = __hold->__as_link();
     __link_nodes_at_back(__nl, __nl);
     ++base::__sz();
 #if _LIBCPP_STD_VER > 14
+#ifndef _LIBCPP_CXX03_LANG
     return __hold.release()->__value_;
+#else
+    return *reinterpret_cast<value_type*>(&__hold.release()->__value_);
+#endif
 #else
     __hold.release();
 #endif
@@ -1955,7 +2068,12 @@
         size_type __ds = 0;
         __node_allocator& __na = base::__node_alloc();
         __hold_pointer __hold = __allocate_node(__na);
+#ifndef _LIBCPP_CXX03_LANG
         __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+        __node_alloc_traits::construct(__na, _VSTD::addressof(
+            *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
         ++__ds;
         __link_pointer __nl = __hold.release()->__as_link();
 #if _LIBCPP_DEBUG_LEVEL == 2
@@ -1971,7 +2089,12 @@
             for (--__n; __n != 0; --__n, ++__e, ++__ds)
             {
                 __hold.reset(__node_alloc_traits::allocate(__na, 1));
+#ifndef _LIBCPP_CXX03_LANG
                 __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+#else
+                __node_alloc_traits::construct(__na, _VSTD::addressof(
+                    *reinterpret_cast<value_type*>(&__hold->__value_)), __x);
+#endif
                 __e.__ptr_->__next_ = __hold.get()->__as_link();
                 __hold->__prev_ = __e.__ptr_;
                 __hold.release();
diff --git a/libcxx/include/optional b/libcxx/include/optional
--- a/libcxx/include/optional
+++ b/libcxx/include/optional
@@ -215,7 +215,7 @@
         "instantiation of optional with a non-object type is undefined behavior");
     union
     {
-        char __null_state_;
+        // char __null_state_;
         value_type __val_;
     };
     bool __engaged_;
@@ -229,7 +229,7 @@
 
     _LIBCPP_INLINE_VISIBILITY
     constexpr __optional_destruct_base() noexcept
-        :  __null_state_(),
+        :  /* __null_state_(), */
            __engaged_(false) {}
 
     template <class... _Args>
@@ -257,14 +257,14 @@
         "instantiation of optional with a non-object type is undefined behavior");
     union
     {
-        char __null_state_;
+        // char __null_state_;
         value_type __val_;
     };
     bool __engaged_;
 
     _LIBCPP_INLINE_VISIBILITY
     constexpr __optional_destruct_base() noexcept
-        :  __null_state_(),
+        :  /* __null_state_(), */
            __engaged_(false) {}
 
     template <class... _Args>