Template specialization for types providing a traits class

Question

I have a class

template <typename T> struct Dispatch;

which is used to call a type-specific function. For instance, assume I have dispatchers like

template <> struct Dispatch <MyClass> {
  static void Apply (void* a, MyClass& m)
  {
      ::memcpy (a, &m, sizeof (m));
  }
};

Now I have a bunch of classes for which I have a type-trait, ArrayTypes. I would like to do something like:

 template <> struct Dispatch <enable_if<IsArrayType>>
 {
   template <typename ArrayType>
   static void Apply (void* a, ArrayType& m)
   {
     ::memcpy (a, &m, ArrayTypeTraits<ArrayType>::GetSize (m));
   }
 };

Is this possible?

Answer 1

Use boost enable_if.

If boost is unavailable, check out the enable_if idiom.