using header files with functors in c++ - c++

Question

I am attempting to use functors in a larger-scope project. I managed to implement a functor when it was on its own, but I am having a lot of trouble figuring out where I define things in the header file (.h) vs the .ccp file so that I can access my functor in the rest of my program. When the functor is all together it appears as such:
class SpecialAttack {
public:
SpecialAttack() {};
virtual bool operator() (double timer) = 0;
};
class BallAttack : public SpecialAttack {
public:
BallAttack() {};
virtual bool operator() (double timer) { return (timer==0); }
};
class SpiderAttack : public SpecialAttack {
public:
SpiderAttack() {};
virtual bool operator() (double timer) { return true; }
};
double special_attack(double timer, SpecialAttack* func) {
return (*func)(timer);
}
I cannot figure out how to break this up into the appropriate files so that I can then reference it in the rest of my code. What parts should i put in the .h file and what parts go in the .ccp file? Thanks!

Answer 1

Splitting functors between .hpp and .cpp files follows the same pattern of declaration and definition used for any class with member functions.
attack.hpp
#pragma once
class SpecialAttack {
public:
SpecialAttack();
virtual bool operator() (double timer) = 0;
};
class BallAttack : public SpecialAttack {
public:
BallAttack();
virtual bool operator() (double timer) override;
};
class SpiderAttack : public SpecialAttack {
public:
SpiderAttack();
virtual bool operator() (double timer) override;
};
attack.cpp
#include "attack.hpp"
SpecialAttack::SpecialAttack() {
}
BallAttack::BallAttack() {
}
/*virtual*/ bool BallAttack::operator() (double timer) /*override*/ {
return (timer==0);
}
SpiderAttack::SpiderAttack() {
}
/*virtual*/ bool SpiderAttack::operator() (double timer) /*override*/ {
return true;
}