<mp-units/ext/type_traits.h>template<
typename T,
auto Vs...>
[[nodiscard]]
consteval
bool
contains();template<
template<typename...> typename T,
typename... Ts>
[[nodiscard]]
consteval
bool
contains();template<
template<auto...> typename T,
typename... Ts>
[[nodiscard]]
consteval
bool
contains();