Emulating public and private in C structs

Consider:
foo.h:
struct Foo {
        int public_1;
        int public_2;
}
struct Foo * create_Foo ();
void bar_Foo (struct Foo*);
/* etc */
foo.c:
#include "foo.h"
struct Foo_private {
        struct Foo foo; /* ??? */
        int private_1;
        int private_2;
}
struct Foo * create_Foo (void) {
        return malloc (sizeof(Foo_private));
}
void bar_Foo (struct Foo *foo) {
        Foo_private *foo_p = (Foo_private*) foo; /* ??? */
        /* do whatever with foo_p->private_1 and foo_p->private_2 */
}
Is there anything wrong with this? I'm dubious about the lines commented with ???. I don't want to write getters and setters for the 'public' stuff.

>>42
Not to mention that the Carolingians didn't come up with it just to be different or to spite people; they came up with it because it was a palpable improvement over the old system. That's why mixed case was individually invented at Constantinople (though the Byzantium comment was just to illustrate the stupidity of thinking a term like ``Frank'' implies a connection with modern-day France) and, albeit in a different form, in Japan. It's also why every alphabetic writing system invented since then has incorporated it. It just makes writing and reading easier.