Question

I learned long ago that the only reliable way for a static member of be initialized for sure is to do in a function. Now, what I’m about to do is to start returning static data by non-const reference and I need someone to stop me.

function int& dataSlot()
{
    static int dataMember = 0;
    return dataMember;
}

To my knowledge this is the only way to ensure that the static member is initlized to zero. However, it creates obscure code like this:

dataSlot() = 7; // perfectly normal?

The other way is to put the definition in a translation unit and keep the stuff out of the header file. I have nothing against that per se but I have no idea what the standard says regard when and under what circumstances that is safe.

The absolute last thing I wanna end up doing is accidently accessing uninitialized data and losing control of my program.

Answer 1

Returning a non-const reference in itself is fairly harmless, for example it’s what vector::at() does, or vector::iterator::operator*.

If you don’t like the syntax dataSlot() = 7;, you could define:

void setglobal(int i) {
    dataSlot() = i;
}
int getglobal() {
    return dataSlot();
}

Or you could define:

int *dataSlot() {
    static int dataMember = 0;
    return &dataMember;
}

*dataSlot() = 7; // better than dataSlot() = 7?
std::cout << *dataSlot(); // worse than std::cout << dataSlot()?

If you want someone to stop you, they need more information in order to propose an alternative to your use of mutable global state!