How to write a type trait `is_container` or `is_vector`?

Question

Is it possible to write a type trait whose value is true for all common STL structures (e.g., vector, set, map, ...)?

To get s

Answer 1

Why not do something like this for is_container?

template 
struct is_container : std::false_type { };

template  struct is_container > : std::true_type { };
template  struct is_container > : std::true_type { };
// ...

That way users can add their own containers by partially-specializing. As for is_vector et-al, just use partial specialization as I did above, but limit it to only one container type, not many.