Instantiation of Base Class.

I'm quiet sure the member data ' testData ' can't be initialized by
Msg::TradeMsg class nor by Msg::OrderMsg class. But wanted to double
check if there is any way, we can instantiate Msg::testData from
TradeMsg && OrderMsg, preserving the class Msg declaration. Sample
code follows:

// Lets preserve the declaration of class Msg as is..
class Msg{
    public:
        int testData;
    public:
        Msg();
        class TradeMsg;
        class OrderMsg;
        ~Msg();
};

class Msg::TradeMsg{
    public:
        TradeMsg(){
                        // Can we instantiate the Msg datamember like
this ?
            testData = 5;
        }

        ~TradeMsg(){

        }
};

class Msg::OrderMsg{
    public:
        OrderMsg(){
            testData = 7; // Again Can we assign value to testData like this ?
        }
};

int main (){
    TradeMsg trdMsg;
    OrderMsg ordMsg;
    return 0;
}

We can instantiate, if class Msg is declared as base and let TradeMsg,
OrderMsg inherit from " Msg ". Can we confirm if inheritance is the
only mechanism to instantiate the data member of class " Msg ".

Thank you for your time. Any help would be greatly appreciated.

Thanks,
-Wg

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