Restrict msvc-12.0 to one tuple in tuple_transform

include/boost/mp11/tuple.hpp

@@ -89,6 +89,41 @@ template<class Tp, class F> BOOST_MP11_CONSTEXPR F tuple_for_each( Tp && tp, F &
 }
 
 // tuple_transform
+
+namespace detail
+{
+
+template<class... T> BOOST_MP11_CONSTEXPR auto tp_forward( T&&... t ) -> std::tuple<T...>
+{
+    return std::tuple<T...>( std::forward<T>( t )... );
+}
+
+} // namespace detail
+
+#if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1900 )
+
+namespace detail
+{
+
+template<class F, class Tp, std::size_t... J>
+BOOST_MP11_CONSTEXPR auto tuple_transform_impl( integer_sequence<std::size_t, J...>, F const& f, Tp&& tp )
+    -> decltype( tp_forward( f( std::get<J>( std::forward<Tp>(tp) ) )... ) )
+{
+    return tp_forward( f( std::get<J>( std::forward<Tp>(tp) ) )... );
+}
+
+} // namespace detail
+
+template<class F, class Tp,
+    class Seq = make_index_sequence<std::tuple_size<typename std::remove_reference<Tp>::type>::value>>
+BOOST_MP11_CONSTEXPR auto tuple_transform( F const& f, Tp&& tp )
+    -> decltype( detail::tuple_transform_impl( Seq(), f, std::forward<Tp>(tp) ) )
+{
+    return detail::tuple_transform_impl( Seq(), f, std::forward<Tp>(tp) );
+}
+
+#else
+
 namespace detail
 {
 
@@ -99,11 +134,6 @@ BOOST_MP11_CONSTEXPR auto tp_extract( Tp&&... tp )
     return std::forward_as_tuple( std::get<J>( std::forward<Tp>( tp ) )... );
 }
 
-template<class... T> BOOST_MP11_CONSTEXPR auto tp_forward( T&&... t ) -> std::tuple<T...>
-{
-    return std::tuple<T...>( std::forward<T>( t )... );
-}
-
 template<class F, class... Tp, std::size_t... J>
 BOOST_MP11_CONSTEXPR auto tuple_transform_impl( integer_sequence<std::size_t, J...>, F const& f, Tp&&... tp )
     -> decltype( tp_forward( tuple_apply( f, tp_extract<J>( std::forward<Tp>(tp)... ) )... ) )
@@ -135,7 +165,9 @@ BOOST_MP11_CONSTEXPR auto tuple_transform( F const& f, Tp&&... tp )
     return detail::tuple_transform_impl( Seq(), f, std::forward<Tp>(tp)... );
 }
 
-#endif
+#endif // BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1910 )
+
+#endif // BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1900 )
 
 } // namespace mp11
 } // namespace boost