operator overloading (prefix ++)

Hi...

I am writing the overloading operator function (prefix ++) according to my book.. but it doesnt work !!!!!!

But if i write:
void operator++()
{
++x;
}
it works !!!!!
Is the book wrong???

Here is my code according to the book that doesnt work as it should:

#include <iostream>
using namespace std;

class things
{
int x,y,z;

public:
void print()
{

cout<<x<<endl;
cout<<y<<endl;
cout<<z<<endl;
cout<<"*****"<<endl;

}
things():x(0),y(0),z(0){};

thing& operator ++() //******** here *******
{
++x;
return *this;
}


};

int main()
{

things table;

cout<<"*****"<<endl;

table.print();

++table;

table.print();

return 0;
}

You have:

Code:

---

thing & operator ++() //******** here *******

---

It should be things &

Also, the problem with the void method is that you can not use operator ++
in many ways that you would expect to .. Example:

Code:

---

things table2 = ++table;

---

Please format your code properly before posting and use code tags (Go advanced, select the code and click '#'). You code as posted is not very readable.

When overloading the operator ++, there are two situations that need to be considered - pre and post increment.
Prefix increment is defined as

Code:

---

things& operator++();

---

whereas postfix increment is defined as

Code:

---

things operator++(int);

---

See
http://msdn.microsoft.com/en-us/library/f6s9k9ta.aspx