C + + Empty class detailed _c language

Null class Default-generated members:
Class Empty {};
Empty (); Default constructor
Empty (const empty&); Default copy constructor
~empty (); Default destructor
empty& operator= (const empty&); Default assignment operator
empty* operator& (); Fetch operator
Const empty* operator& () const; Address operator Const

Give an example:

Copy Code code as follows:

#include <iostream>
using namespace Std;

Class Empty
{
Public
Empty *operator& ()
{
cout<< "AAAA" <<endl;
return this;
}
Const empty* operator& () const
{
cout<< "BBBB" <<endl;
return this;
}
};

int main (void)
{
Empty e;
Empty *p=&e;
Const EMPTY E2;
Const Empty *p2=&e2;
Cout<<sizeof (Empty) <<endl;
}

Run Result:

Visible:
Empty *p=&e called the empty* operator& () operator function
The const empty* operator& () const operator function is invoked by the const Empty *P2=&E2.
The size of the empty class is 1 bytes.