[Boost-users] How to test if a type is of some form?

Hi, I want to test if template argument is of some form like in the following code. I could define some helper class to do such test. But I'm wondering if there is any easy to do it with boost? The type_traits's is_same does not work in this case. I'm wondering if there could be some generalization of it. template <T> void f() { //For example, I want to test if T is of the // form of std::complex<S> } Thanks, Peng