std::experimental::void_t
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Defined in header
<experimental/type_traits>
template< class... >
using void_t = void;
(library fundamentals TS v2)
using void_t = void;
A utility metafunction that maps a sequence of any types to the type void.
[edit] Notes
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 and the LFTS v2 is based on C++14.