Yet another template class question (corrected)

I am writing a template HashTable class. I have got it working, but I
want to make the code more generic and more robust. The current code
looks something like this:

template <class InnerType, class KeyType, class KeyToSizeT>
class myHash
{
    // Impl here
};

Where:

InnerType is the data type being stored
KeyType is the data type of the hash key
KeyToSize is the function that returns the size of the hash key

I am now mandating that InnerType MUST implement interface IHashable:

class myHashKey
{
     virtual bool operator==(const myHashKey& key) const = 0 ;
     virtual size_t Size() const = 0 ;
};

class IHashable
{
     virtual const myHashKey* GetKey() const = 0 ;
     virtual bool IsKeyEqual(const myHashKey* key) const = 0;
     virtual size_t KeySize() const = 0 ;
};

With this new policy, I want to be able to simplify my HashTable class to:

template <class InnerType>
class myHash
{
    //Ho do I reference KeyType and KeyToSizeT now ?
    // Impl here
};