Forward declaration of a structure in C

What do you think of following code?

/*
 * decl.h
 */
struct junk {
    int a;
};

----------------------------------------------
/*
 * fwd.c
 * We have not included the header file decl.h.
 */
#include 
struct junk;

int main()
{
    struct junk *ptr;
    printf("%d", ptr->a);
}

You will get compilation error that structure object ptr is incomplete. This is misleading if you do not go through all included header files. cscope will make you believe that definition exists. You just wonder till you find out that structure was never defined in fwd.c!

Advertisements

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s