Type safe enum bit flags

Question

I\'m looking to use a set of bit flags for my current issue. These flags are (nicely) defined as part of an enum, however I understand that when you OR

Answer 1

Does this overload really provide type safety?

In this case, yes. The valid range of values for the enumeration goes at least up to (but not necessarily including) the next largest power of two after the largest named enumerator, in order to allow it to be used for bitmasks like this. So any bitwise operation on two values will give a value representable by this type.

Does casting an int containing values not defined in the enum cause undefined behaviour?

No, as long as the values are representable by the enumeration, which they are here.

Are there any caveats to be aware of?

If you were doing operations such as arithmetic, which could take the value out of range, then you'd get an implementation-defined result, but not undefined behavoiur.