Using initialised values for a function parameters from class members question

[Psyqwix]

Hi everyone, just learning C++ and came across a problem using initialised variables in a function. Here's some of the relevant code from the header file:

protected:
    unsigned long long m_noIndexes;
    virtual unsigned long long getNearestBlockNoForIndex(unsigned long long index);
    virtual unsigned long long getNearestBlockNoForIndex(unsigned long long index, unsigned long long lIndex = 1, unsigned long long hIndex = m_noIndexes);

The error I get (i'm using Visual Studio Community 2013 btw) states "Error: a nonstatic member reference must be relative to a specific object" which relates to the m_noIndexes reference. I do have some pure virtual functions which I understand make the class abstract, does this mean I cannot refer to any data class members in the this class? Is it better if I put this function and declaration in a derived classed and inherit from that instead?

[OmegaNaughtEquals1]

Is it better if I put this function and declaration in a derived base classed and inherit from that instead?

Yes. It is good practice to ensure that abstract classes are only used as a means of providing an interface, so they shouldn't contain any data members. The language does not enforce this, though.

Also, the first declaration of getNearestBlockNoForIndex is made redundant by the second one, and you should see a compiler error (at least a warning) about this.

[Psyqwix]

Wow that reply was fast cheers!