Question about keyword "this" in tutorial

[BananaCode]

Hello,

I'm stuck at a part of the tutorial. Here is the code:

#include <iostream>
using namespace std;
class CDummy {
public:
int isitme (CDummy& param);
};
int CDummy::isitme (CDummy& param)
{
if (&param == this) return true;
else return false;
}
int main () {
CDummy a;
CDummy* b = &a;
if ( b->isitme(a) )
cout << "yes, &a is b";
return 0;
}

What I do not understand is, what does "CDummy& param" in the functions parameters exactly mean? The part which confuses me is the "&" sign. Can someone comment the important parts in the steps and say what these lines do?

Thank you.

[hamsterman]

That's passing by reference. It was mentioned in http://www.cplusplus.com/doc/tutorial/functions2/

[BananaCode]

Ah yes, I forgot about that. The entire code makes now sense. Is it correct to say that instead of writing "b->isitme(a)" I could write "a.isitme(a)" ?

[Bazzy]

Arrow operator -> is for pointers, dot operator . is for references/objects

[BananaCode]

So...yes?

[Bazzy]

b is a pointer. why don't you try to see what happens?

[BananaCode]

I did, I get the same output. But just to make sure I wanted to ask.