#include <iostream>


using namespace std;


class A {
  public:
    enum Mode {ModeA, ModeB, ModeC};

   // ... // other methods, constructor etc

    void setMode(Mode m) {
      mMode = m;
    }

  private:
    Mode mMode;
};

int main(int argc, char **argv) {
  A a;
  a.setMode( (A::Mode) (A::ModeA  | A::ModeC ));

  return 0;
}