OPP_NEW_IDEA

typedef struct Object {
    int a;
    int ID;
    int b;
}Object;
Object newObject() {
    Object obj;
    printf("newObject()...
");
    obj.a = 1024;
    obj.ID = -1;
    obj.b = 2;
    return obj;
}
Object newObjectWithID(int ID) {
    Object obj;
    printf("newObjectWithID()...
");
    obj = newObject();
    obj.ID = ID;
    return obj;
}
typedef struct User {
    Object obj;
    int c;
}User;
User newUser() {
    User user;
    printf("newUser()...
");
    user.obj = newObject();
    user.c = 3;
    return user;
}
User newUserWithID(int ID) {
    User user;
    printf("newUserWithID()...
");
    user = newUser();
    user.obj = newObjectWithID(ID);
    
    return user;
}