Index: include/vector
===================================================================
--- include/vector
+++ include/vector
@@ -355,6 +355,7 @@
     __vector_base()
         _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
     _LIBCPP_INLINE_VISIBILITY __vector_base(const allocator_type& __a);
+    _LIBCPP_INLINE_VISIBILITY __vector_base(allocator_type&& __a);
     ~__vector_base();
 
     _LIBCPP_INLINE_VISIBILITY
@@ -438,6 +439,15 @@
 {
 }
 
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+__vector_base<_Tp, _Allocator>::__vector_base(allocator_type&& __a)
+    : __begin_(nullptr),
+      __end_(nullptr),
+      __end_cap_(nullptr, std::move(__a))
+{
+}
+
 template <class _Tp, class _Allocator>
 __vector_base<_Tp, _Allocator>::~__vector_base()
 {