Address of Methods

[tcollins]

Also, does anyone know how to take the Address of a Method? I have a method inside a C++ Class that another function needs to call as a function pointer.

 

[xwb]

Just use the method name without the parameters. If it is within a class, make the method static.

 

[Zyrenthian]

Here is a proof of concept that shows method pointers in use. The use of static is not required.

Matt

#include <iostream.h>

class c1{
public:
	c1::c1(){}
	void sample1();
	void sample2();
	void sample3();
	void sample4();
	void sample5();
	void sample6();

};

void c1::sample1(){cout<<&quot;sample1\n&quot;;}
void c1::sample2(){cout<<&quot;sample2\n&quot;;}
void c1::sample3(){cout<<&quot;sample3\n&quot;;}
void c1::sample4(){cout<<&quot;sample4\n&quot;;}
void c1::sample5(){cout<<&quot;sample5\n&quot;;}
void c1::sample6(){cout<<&quot;sample6\n&quot;;}

class c2{
public:
	c2::c2( void(c1::*ptr)() ):method_ptr(ptr){};
	void setmethod(void(c1::*ptr)());
	void fire();
private:

	void (c1::*method_ptr)();  
};


class c3{
public:
	c3::c3():method_ptr(fxna){};
	void setmethod(int x);
	void fxna(){cout<<&quot;fxna\n&quot;;}
	void fxnb(){cout<<&quot;fxnb\n&quot;;}
	void fxnc(){cout<<&quot;fxnc\n&quot;;}
private:

	void (c3::*method_ptr)();  
};

void c2::fire(){c1 temp;(temp.*method_ptr)();}
void c2::setmethod(void(c1::*ptr)()){method_ptr=ptr;}
void c3::setmethod(int x){
	switch(x)
	{ 
	case 1:method_ptr = fxna;break;
	case 2:method_ptr = fxnb;break;
	case 3:
	default:method_ptr = fxnc;break;
	}
}


int main()
{
	c2 mc2(&c1::sample1);

	mc2.fire();
	mc2.setmethod(&c1::sample2);
	mc2.fire();
	mc2.setmethod(&c1::sample3);
	mc2.fire();
	mc2.setmethod(&c1::sample4);
	mc2.fire();
	mc2.setmethod(&c1::sample5);
	mc2.fire();
	mc2.setmethod(&c1::sample6);
	mc2.fire();

	c3 mc3;

	cout<<&quot;\n\n\n\nbeginning\n\n\n\n&quot;;
	mc3.setmethod(1);
	mc3.setmethod(2);
	mc3.setmethod(3);



	return 0;
}