Thanks to K-ballo for noting a second incorrect noexcept clause in tuple - and suggesting a more correct way to write the first git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@217884 91177308-0d34-0410-b5e6-96231b3b80d8 
diff --git a/include/tuple b/include/tuple index 8ccec56..1463170 100644 --- a/include/tuple +++ b/include/tuple 
@@ -554,12 +554,12 @@  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11  tuple(_Up&&... __u)  _NOEXCEPT_(( - is_nothrow_constructible<base( + is_nothrow_constructible<base,  typename __make_tuple_indices<sizeof...(_Up)>::type,  typename __make_tuple_types<tuple, sizeof...(_Up)>::type,  typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type,  typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type, - _Up...) + _Up...  >::value  ))  : base_(typename __make_tuple_indices<sizeof...(_Up)>::type(), @@ -595,7 +595,7 @@  explicit  tuple(_Up&&... __u)  _NOEXCEPT_(( - is_nothrow_constructible< + is_nothrow_constructible<base,  typename __make_tuple_indices<sizeof...(_Up)>::type,  typename __make_tuple_types<tuple, sizeof...(_Up)>::type,  typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type,