Using C flag enums in C++

Question

I have a C API that defines an enum like so:

typedef enum
{
  C_ENUM_VALUE_NONE    = 0,
  C_ENUM_VALUE_APPLE   = (1 << 0),
  C_ENUM_VALUE_BANANA  = (1          


        

Answer 1

You need to cast ints to enums in C++, but you can hide the cast in a custom OR operator:

CEnumType operator|(CEnumType lhs, CEnumType rhs) {
    return (CEnumType) ((int)lhs| (int)rhs);
}

With this operator in place, you can write your original

do_something(C_ENUM_VALUE_APPLE | C_ENUM_VALUE_BANANA);

and it will compile and run without a problem.