cout<<"m: " << month_tbl[m]<<endl;  // March?

Ich habe dem Objekt m im Hauptprogramm doch den Wert 2 geben.

#include <iostream>
using namespace std;

//------------------------------------------------------------------------------

enum Month {
	jan=1, feb, mar, apr, may, jun, jul, aug, sep, oct, nov, dcm
};

//------------------------------------------------------------------------------

ostream& operator<<(ostream& os, Month m)
{
	static const char* month_tbl[12] =
	{
		"January","February","March","April","May","June","July",
		"August","September","October","November","December"
	};

	cout<<"m: " << month_tbl[m]<<endl;  // March?
	return os << month_tbl[m-1];
}

//------------------------------------------------------------------------------

int main()
{

	Month m = 2;  //  Month m = feb;
	cout << m << endl;

	cin.get();
	return 0;
}

//------------------------------------------------------------------------------