[mrighele]

I haven't been using C++ for a number of years but I think you could set the default values of fields even back then. Something like

    struct test {
        int my_int = 0;
        int* my_ptr = std::nullptr;
    };

Or is this something more recent ?

You cannot initialize them with a different value unless you also write a constructor, but it not the issue here (since you are supposed to read them from the file system)

[MrRadar]

That's C++11 syntax. Before then you'd have to manually initialize them in every constructor, with a hand-written default constructor as a minimum:

    struct test {
        int my_int;
        int *my_ptr;
        
        test() : my_int(0), my_ptr(NULL) {}
    };