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
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.
a++ is equivalent to a.operator++(0);. Your code is valid
13.5/7
When the postfix increment is called as a result of using the ++ operator, the int argument will have value zero.
Yes, it is valid the int as a parameter it only a policy enforcing parameter to distinguish between prefix and postfix operators. The passed parameter will be received as an argument, which is the behavior you see & it is prfectly defined behavior.
