Question

Please look at inheritance:

interface IArray
{
   virtual unsigned __int8* GetAddress() const = 0;

   virtual unsigned int GetItemCount() const = 0;

   virtual unsigned int GetItemSize() const = 0;
};

template<class T>
class CustomArrayT : public IArray
{
public:

   virtual unsigned __int8* GetAddress() const;

   virtual unsigned int GetItemCount() const;

   virtual unsigned int GetItemSize() const;


   T& GetItem(unsigned int index);
};

interface IFloatArray : public CustomArrayT<float>
{
   virtual IFloatArray* GetCompressedData() const = 0;
};

class ShannonFloatArray : public IFloatArray
{
public:

   virtual IFloatArray* GetCompressedData() const;
};

class FourierFloatArray : public IFloatArray
{
public:

   virtual IFloatArray* GetCompressedData() const;
};

class MickyMouseFloatArray : public IFloatArray
{
public:

   virtual IFloatArray* GetCompressedData() const;
};

Main goal of the question is inheritance IFloatArray -> CustomArrayT: interface inherits some none abstract class. I do not want to support multiple inheritance. But I need all downtree classes has functionality of class CustomArrayT and implementing interface IFloatArray.

What pros and cons of such tree?

How could it be done by another way? Maybe some pattern?

Answer 1

I would do it like this:

template<class T>
class IArray {
public:
  virtual int size() const=0;
  virtual T map(int index) const=0;
};

All the pointers are just unnecessary.