QVM: Quaternions, Vectors, Matrices

namespace
boost
{
    namespace
    qvm
    {
        template <class T>
        struct is_quat
        {
            static bool const value=/*unspecified*/;
        };
    }
}

This type template defines a compile-time boolean constant value which can be used to determine whether a type T is a quaternion type. For quaternion types, the quat_traits template can be used to access their elements generically, or to obtain their scalar type.