Question

I’ve learned that putting enums in namespaces avoids compiling errors when two enums share one equaly named item.

namespace Feeling
{
    enum e
    {
        Happy = 1,
        Sad = 2,
        Blue = 4,
        Angry = 8,
        Mad = 16
    };
}

So you can pass it to functions that are declared like

void HowDoYouFeel(Feeling::e feeling);

But when trying to OR it like this:

HowDoYouFeel(Feeling::Happy | Feeling::Blue);

I get an error. What is the best way to handle this?

Answer 1

The question asks for “the best methd”, which is a bit subjective. I write e operator|(e left, e right) { return e(int(left)|int(right)); } for these cases, to make clear that Feeling::e has an orthogonal encoding.