How to mutually link two structures?

[DustyMx]

Hi guys, I would like to know if it is possible to declare two structures where struct1 has a pointer to struct2 and struct2 has a pointer to struct1, if it is possible how they should be declared?

typedef struct _AAA {
BBB *p_bbb;
} AAA;

typedef struct _BBB {
AAA *p_aaa;
} BBB;

Thanks

 

[DaveSinkula]

One way:

typedef struct _BBB BBB;
struct _AAA
{
   BBB *p_bbb;
};

typedef struct _AAA AAA;
struct _BBB
{
   AAA *p_aaa;
};

Another way:

struct _BBB;
struct _AAA
{
   struct _BBB *p_bbb;
};

struct _BBB
{
   struct _AAA *p_aaa;
};

 

[butthead]

could you not use a void pointer as in

typedef struct _AAA {
void *p_bbb;
} AAA;

typedef struct _BBB {
void *p_aaa;
} BBB;

it woould require a little more work later when
working with the code but you would not have to
wory about having a structure defined in one case
before you could use it in the declaration of the
other.

TC

 

[butthead]

are we assured that globals are created in the
order that we list them. I seem to recall that
we cannot assume what order the compiler will
process globals. and occasionally this will lead to
our assumptions creating a bug. we get away with it
most of the time but then there is that one time.

kinda like returning a pointer to a non static
char array.

TC

 

[DaveSinkula]

are we assured that globals are created in the order that we list them.

For objects, no. But this is about data types.