15 template <
typename... Args>
20 static constexpr
bool value =
false;
23 template <
typename last>
25 static constexpr
bool value =
false;
28 template <
typename first,
typename second,
typename... others>
35 static constexpr
bool value = _first or _second;
38 template <
typename first,
typename... others>
40 static constexpr
bool value =
true;
44 template <
typename... Args>