Overloading unary operators using pointers

[Niels_M]

Hi

Please take a look at this non-compilable example:

#include <iostream.h>

class test{
public:
	int a;
	friend operator++(test *b);
};

operator++(test *b)
{
	b->a=b->a+1;
}

int main()
{
	test asd;
	asd.a=1;
        &asd++;

	return 0;
}

This will only compile if I replace the pointer *b with a reference. In my book it says that the reason why that is the case is because "&asd++ is inherently ambigous", but explains it no further.

What does the author mean by that?

Best,
Niles.