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

If you want to use explicit PMF ( or at least see how they are used):

Declare the PMF type:

class Row 
{
    public:
    typedef string (Row::*getFilter)() const;
     // etc.
};

class Table
{
    public:
    // Call it like this:

    vector pmf_filterX(string s)
    {
        return filter(s, &Row::getX);
    }
    private:
    // Use it like this:
    vector filter(string s, Row::getFilter f)
    {
        vector result;
        vector::iterator it;
        for(it = d_table.begin(); it != d_table.end(); ++it)
            {
            const Row& row = *it;

            if ((row.*f)() == s) 
                {
                int val = it->getVal();
                result.push_back(val);
                }
            }
        return result;
    }
};