Question

Consider following example:

class CBase abstract
{
protected:
    CBase() { }
};

I could get rid either of the protected constructor or the ‘abstract‘ keyword. The keyword is intuitive to use, but as far as I know, it isn’t supported by other compilers (especially Gcc).

I was also wondering if using some kind of macro to prepare this code for g++ compilation would be easy enough to write. I want to minimalize code changes if I ever wanted to compile my code on system other than MS Windows.

Answer 1

What about a pure virtual destructor with an empty definition, i.e.

class CBase {
public:
  virtual ~CBase() = 0;
}

inline CBase::~CBase() {}

Any not-even-decent C++ compiler supports this and the standard allows it.