class ofApp : public ofBaseApp{

public:
    void setup();
    void update();
    void draw();

    int addition (int a);
    int operation (int a, int (*f)(int));
};

void ofApp::setup(){
    operation(1, std::bind(&ofApp::addition, this));
}

int ofApp::addition (int a){
    return (a+a);
}

int ofApp::operation (int a, int (*f)(int)){
    int g = 0;
    g = (*f)(a);
    return (g);
}