void return_array(char *arr, int size) {

    for(int i = 0; i < size; i++)

        arr[i] = i;

}

​

int main() {

    int size = 5;

    char arr[size];

    return_array(arr, size);

}

// fill a preallocated buffer provided by 

// the caller (caller allocates buf and passes to the function)

void foo(char *buf, int count) {

    for(int i = 0; i < count; ++i)

        buf[i] = i;

}

​

int main() {

    char arr[10] = {0};

    foo(arr, 10);

    // No need to deallocate because we allocated 

    // arr with automatic storage duration.

    // If we had dynamically allocated it

    // (i.e. malloc or some variant) then we 

    // would need to call free(arr)

}