Use object as param for class method in cpp

class_a.cpp

#include <stdio.h>
#include "class_a.h"

A::A(void) {
}

A::~A(void) {

}

void A::init(B * test) {
	printf("result of call init() is '%s'\n", test->test());

}

class_a.h

#include "class_b.h"
#ifndef _CLASS_A_
#define _CLASS_A_ 1
class A
{
    public:
    A(void);
    ~A(void);
    void init(B* test);
};
#endif

class_b.cpp

#include "class_b.h"

char * B::test(void) {
	return "test";
}

class_b.h

#ifndef _CLASS_B_
#define _CLASS_B_ 1

class B {
    public:
        char * test(void);
};
#endif

gistfile1.txt

$ g++ ./main.cpp ./class_a.cpp ./class_b.cpp -o main.a                                                                                                       
./class_b.cpp: In member function ‘char* B::test()’:
./class_b.cpp:4:9: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
$ ./main.a                                                                                                                                                   
result of call init() is 'test'

main.cpp

#include "class_a.h"
#include "class_b.h"

int main() {
    A *a_obj = new A();
    B *b_obj = new B();
    a_obj->init(b_obj);
    return 0;
}