oop in C

main.c

#include <stdlib.h>
#include <cstdio>


typedef struct {
    int age;
    char *name;

    void (*eat)(const void *self);
} Animal;


void eat(const void *animal) {
    printf("%s is eating\n", ((Animal *) animal)->name);
}

Animal * new_Animal(int age, char *name) {
    Animal *object = (Animal *) malloc(sizeof(Animal));
    object->age = age;
    object->name = name;
    object->eat = eat;
    return object;
}

typedef struct {
    Animal base;
    void (*fly)(const void *self);
} Bird;

void fly(const void *animal) {
    printf("%s is flying\n", ((Animal *) animal)->name);
}
Bird * new_Bird(int age, char *name) {
    Animal *object = (Animal *) malloc(sizeof(Animal));
    object->age = age;
    object->name = name;
    object->eat = eat;
    Bird * bird = (Bird *) malloc(sizeof(Bird));
    bird->base = *object;
    bird->fly = &fly;
    return bird;
}

int main() {
    Bird * object = new_Bird(18,"tom");
    ((Animal *)object)->eat(object);
    ((Bird *)object)->fly(object);
    return 0;
}