pointer to member function

Question

I am trying to generalize the functions filterX() and filterY() in the following class Table to function filter().

Answer 1

Here is how to do it by using pointer to member functions:

// helper to avoid type nightmare;
typedef string (Row::* GetterP)() const;

class Table 
{ 
public: 
    void add(string x, string y, int val); 

    // Define a templated function that can be called with GetX or GetY
    template 
    vector filter(string s)
    {
         int i = (d_table[i].*getter)(); // how to use getter in filter
    }

private:
    vector d_table;  
};

// Usage:
Table t;
t.filter<&Row::GetX>("");