Question

I am not using this code in any production environment, it is just for my understanding. Is this code valid (i.e. can I define my postfix operator like this?):

class A
{
public:
    A& operator++(int n)
    {
        std::cout<<"N is:"<<n<<"\n";
        return *this;
    }
};


int main()
{   
    A a;
    a++;
    a.operator ++(10);
}

On VS2008, I get the output as:

N is 0

for first call and

N is 10

for second call

Answer 1

This behavior is legal and well defined in 13.5.7:

Calling operator++ explicitly, as in
expressions like a.operator++(2), has
no special properties: The argument to
operator++ is 2.