Overload a C++ function according to the return value

Question

We all know that you can overload a function according to the parameters:

int mul(int i, int j) { return i*j; }
std::string mul(char c, int n) { return std::string(n, c); } 

Can you overload a function according to the return value? Define a function that returns different things according to how the return value is used:

int n = mul(6, 3); // n = 18
std::string s = mul(6, 3); // s = "666"
// Note that both invocations take the exact same parameters (same types)

You can assume the first parameter is between 0-9, no need to verify the input or have any error handling.

question from:https://stackoverflow.com/questions/226144/overload-a-c-function-according-to-the-return-value

Answer 1

class mul
{
public:
    mul(int p1, int p2)
    {
        param1 = p1;
        param2 = p2;
    }
    operator int ()
    {
        return param1 * param2;
    }

    operator std::string ()
    {
        return std::string(param2, param1 + '0');
    }

private:
    int param1;
    int param2;
};

Not that I would use that.