passing of structure with pointer member in function is shallow copy or deep copy In C

Question

In C++, there is overloaded copy constructor and assignment overloading for a deep copy. Since default available is a shallow copy.

In C, the structure which has pointer member, if passed to a function or assigned to already created new struct object is a deep copy or shallow copy??

E.g

struct data {
    int a;
    int *b;
};

void test_func(struct data tes)
{

    tes.a =3;
    int *c = new int[1];
    c[0]=2;
    tes.b =c;
    std::cout<<*tes.b;

}
int main() {
    struct data test;
    int *c = new int;
    *c=4;

    test.a = 1;
    test.b =c;



    std::cout<<*test.b;
    test_func(test);

    std::cout<<*test.b;

}

Passing by value always copies. And C have no concept of "deep" or "shallow" copying, what it does is basically a `memcpy` call. — Some programmer dude, May 31 '18 at 07:00
@KillzoneKid Sure. You're also supposed to use `printf`. And to free memory you allocate. — melpomene, May 31 '18 at 07:09
Tagging a post both C and C++ will get you more views, but it will also annoy a lot of people. — schaiba, May 31 '18 at 08:24

score 5 · Accepted Answer · answered May 31 '18 at 07:05

A structure in C is simply copied as with memcpy. So you get a copy of the pointer but not a copy of the content which is the pointer pointing to. There is nothing different to c++ in that case.

In C you can also write a function for "deep copy" if you like. Every kind of OOP can be done with C but you have to write each and everything by hand.

passing of structure with pointer member in function is shallow copy or deep copy In C

1 Answers1