std::experimental::void_t (3) - Linux Man Pages
Defined in header <experimental/type_traits>
template< class... > (library fundamentals TS v2)
using void_t = void;
A utility metafunction that maps a sequence of any types to the type void.
This utility metafunction is used in template metaprogramming to detect ill-formed types in SFINAE context. First voted into C++17 as std::void_t, it was later added as well to the library fundamentals TS as std::experimental::void_t, because it is a dependency of the detection_idiom.
void_t void variadic alias template