C++ two header files include each other

Question

There are three .h files

A.h:

#ifndef __A_H__
#define __A_H__

#include"Card.h"
#include"B.h"

struct A{
    Card card;
    .....
};

void getCards(A *a, int num);

#endif

B.h

#ifndef __B_H__
#define __B_H__

#include"Card.h"
#include"A.h"

struct B{
    Card card;
    .....
};

void getCards(A *a, B *b, int num);

#endif

Card.h

#ifndef __CARD_H__
#define __CARD_H__

struct Card{
    int num;
    char *type;
};

#endif

Since A.h and B.h includes each other, not all header files are included.

Please give me some advices.

what do you mean by "not all header files are included." ??? — theadnangondal, Mar 19 '15 at 10:27
@EdChum : I did a quick search, but didn't find an answered question that I would consider canonical to address the op's question. Maybe I haven't looked hard enough though - it feels like it should exist. — Sander De Dycker, Mar 19 '15 at 10:28
@theadnangondal `A.h` includes `B.h`. Since there is `#ifndef` statement ,`B.h` is not compiled — soonoo, Mar 19 '15 at 10:31
yeah sure ... well the header files are not compiled but yes, I got your point .. seem like the answer provided by @EdChum can solve your problem ... ie `forward declaration` — theadnangondal, Mar 19 '15 at 10:34

score 2 · Answer 1 · answered Mar 19 '15 at 10:29

As far as I can see, you don't need to include "B.h" in your "A.h" file. So remove it to reduce dependencies. Including "A.h" in your "B.h" file also seems unnecessary. A simple forward declaration should be sufficient.

B.h

#ifndef __B_H__
#define __B_H__

#include"Card.h"

class A; // then you will have to include A.h in your B.cpp file

struct B{
    Card card;
    .....
};

void getCards(A *a, B *b, int num);

#endif

C++ two header files include each other

1 Answers1