\brief Returns the number of template arguments for given class template specialization, or -1 if type \c T is not a class template specialization.
Variadic argument packs count as only one argument, and can not be inspected further.
See Implementation
\brief Returns the number of template arguments for given class template specialization, or -1 if type \c T is not a class template specialization.
Variadic argument packs count as only one argument, and can not be inspected further.