struct pointer in C

LuderForChrist · 01-06-2005, 03:01 PM

I have been told that the only way to pass a structure from one class to another is through using a pointer.

Am I doing this correctly

foo.h

Code:

 
typedef struct foo_str *foo;

foo.c

Code:

struct foo_str
{
   int blah
   float blaha
}foo_str;

calc.h

Code:

typedef struct calc_str *calc;

calc.c

Code:

struct calc_str
{
   foo *mypointer;
   int count;
}calc_str;

... later in a function  
food = foo.blah;

thanks again!

itsme86 · 01-06-2005, 03:42 PM

Your code actually has nothing to do with classes, which actually don't even exist in C. I also don't see any definition of food which you're using calc.c

Traditionally, struct definitions go in the header file, and you can include one struct inside another without the use of a pointer. Your typedef'ing is also a bit weird.

For instance, you can do this:

Code:

// foo.h

#ifndef FOO_H_
#define FOO_H_

struct foo_str
{
  int blah;
  float blaha;
};

typedef struct foo_str foo;

#endif // FOO_H_

Code:

// calc.h

#ifndef CALC_H_
#define CALC_H_

#include "foo.h"

struct calc_str
{
  foo foostuff;
  int count;
};

typedef struct calc_str calc;

#endif // CALC_H_

Code:

// calc.c

#include "foo.h"
#include "calc.h"

int main(void)
{
  calc mycalc;

  mycalc.foostuff.blah = 86;

  return 0;
}

LuderForChrist · 01-07-2005, 07:44 AM

Thanks, What if in another file other than the other two, I have a calc myclalc, a calc hiscalc, and a calc hercalc?

Im getting a first defined here error.

EDIT: Fixed nevermind THANKS!!!