switch with repeating cases?

[acppdummy]

Well g++ didn't like it either:

error: duplicate case value

I suppose I could break it up by inserting some more switches like this?

switch(mycase){
                    case 0: { code for case 0; } break;
                    case 1:
                    case 2: {
                        common code for case 1 and 2;
                    }
                    break;
            }
            switch(mycase){
                    case 2: {
                        code only for case 2;
                    }
                    break;
             }

Or is there a way to turn off the "strict" mode in g++?