C function calls inside struct without using the same object

Question

For example, I have the C code below:

#include <stdio.h>
#include <stdlib.h>
struct a
{
    void(*fun)(struct a *);
    int x;
};

void fun(struct a *st)
{
    ++st->x;
}

struct a *new_a()
{
    struct a *v = (struct a*)malloc(sizeof(struct a));
    v->fun = fun;
    return v;
};

int main()
{
    struct a *v = new_a();
    v->x = 5;
    v->fun(v);
    printf("%d\n", v->x);
}

This prints, of course, 6, however, is there a way of not making the function call dependent of using the same struct to call it: v->fun();, rather than v->fun(v);?

Answer 1

The short answer is no. You would need C++ for that.

Answer 2

No. In C there is no easy way to do this. C++ provides this feature, it's called methods. If you are going to implement your own C with classes, you'll run into a syntax nightmare, before giving up.

A good C-style approach to object-functions will be the convention for functions taking one (mostly the first) parameter as a "self" (which is the reference to the object that gets managed).