Question

Is it possible to emulate object methods in C? I’d like to be able self-reference a structure as a parameter to a member function argument e.g.:

struct foo {
    int a;
    int (*save)(struct foo *);
};

int
save_foo(struct foo *bar) {
    // do stuff.
}

struct foo *
create_foo() {
    struct foo *bar = malloc(sizeof(struct foo));
    bar->save = save_foo;

    return bar;
}

int
main() {
    struct foo *bar = create_foo();

    bar->a = 10;
    bar->save();
}

Where, bar->save(), actually calls save_foo(bar). Seems like a long shot, but it’d be pretty slick 🙂

Answer 1

No, this is not possible. There are object-oriented libraries in C, but they pass the “this” object to the “method” explicitly as in

bar->save(bar);

See the Berkeley DB C API for an example of this style, but do consider using C++ or Objective-C if you want to do OO in a C-like language.