Overloading the ++ operator for a struct pointer

Hi,

I would like to overload the ++ operator for a pointer to a structure, so I can jump from one structure the the other.

Example code:

struct MyHeader
{
char length1;
char length2;
};

// &MyHeader + Length1 + Length2 + sizeof(MyHeader) = the memory adres where I can find the next header.
// example: 0x44444444 + 10 + 20 + 2 = 0x44444476

MyHeader *Header;
Header = (MyHeader)0x44444444; // some memory adres where there is a struct of the MyHeader kind.
// 0x44444444: 10
// 0x44444445: 20
// 0x44444476: 30
// 0x44444477: 40

Header->length1; // should be 10
Header++; // moving to the next header
Header->length1; // should be 30

So how can I overload the ++ operator for *MyHeader? Is this even possible?

sincerly,
Erik M.

generaldustyAsked: 2004-03-29

Who is Participating?

LVL 15

efnCommented: 2004-03-29

No, you can't do exactly that, but you can do something like it. The usual approach is to define an iterator class and use iterators instead of pointers. Then you can overload operators in the iterator class to do what you want. I'll show you what a class declaration might look like to get you started.

class MyHeaderIterator
{
public:
MyHeaderIterator();
MyHeaderIterator(MyHeader* inptr);
MyHeader& operator *();
MyHeader* operator ->();
MyHeaderIterator& operator ++(); // Prefix
MyHeaderIterator& operator ++(int); // Postfix
private:
MyHeader* ptr;
};

--efn

LVL 48

AlexFMCommented: 2004-03-29

You don't need to do this, C++ compiler does this exactly as you want.

MyHeader *Header = ...;
Header++; // adds sizeof(MyHeader) to Header

generaldustyAuthor Commented: 2004-03-29

efn:
I was kinda hoping to avoid that solution, but if that's the only way so be it....

thnx for the quick reply, you get the point ;)

sincerly
Erik M.