#include <iostream>

using namespace std;

class Adat
{
	int a1;
	float a2;
public:
	Adat();
	static int Compare_By_Field1(const Adat&, const Adat&);
};

//int (*CBF) (const Adat&, const  Adat&) = NULL; // ez egy függvénypointer
/** 
 * Version 1
 */
int (*CBF)(const Adat&, const Adat&) = Adat::Compare_By_Field1;

/**
 * +1, ha b nagyobb mint a
 */
int Adat::Compare_By_Field1(const Adat& a, const Adat& b)
{
	if (a.a1 < b.a1) return +1;
	else if (a.a1 > b.a1) return -1;
	else return 0;
}

//CBF=Adat::Compare_By_Field1;

int main()
{
	/**
	 * Version 2
	 */
	CBF = Adat::Compare_By_Field1;
	
	return 0;
}