Thread: Looking for help with pointer idea.

Well, I don't really know how to explain this other than show you so that is what I'll do.

Code:

int* a = new int(1000);
int* b = a;

delete a; a = 0;

I know that doesn't make any sense, but what I am wanting to do is that when a is freed b is automatically set to NULL also.

I am also wanting to maintain the pointer syntax for the most part so I don't end up with another class that is unreadable. I also need to have it work on multiple levels. So basically

Code:

int* a = new int(1000);
int* b = a;
int* c = b;
//etc etc

I want c and b to be set to null when a is freed.

I have been thinking about this for several hours, but I have yet to come up with anything that lets me maintain the regular syntax.

- I don't care about allowing directly newing or deleteing the data as a function for this is fine
- I want to maintain the * and -> to access the data for getting/setting

I am hoping someone here can give me some insight/ideas on how to achieve this. I am very grateful for any assistance. Thank you.

About the second question, using:

int* &b = a;
int* &c = b;

Originally Posted by laserlight

That will only work if b (and c) will never be bound to another pointer.

I just try writting some codes to reach it:

Code:

#include <iostream>
using namespace std;

class myintpointer{
	public:
		myintpointer(){
			p2 = 0;
			p = 0;
		}
		myintpointer(int* p){
			this->p = p;
			p2 = this;
		}
		operator int* (){
			if (p2==this)
				return p;
			else
				return *p2;
		}
		int* operator = (int *p){
			this->p = p;
			p2 = this;
		}
		myintpointer* operator = (myintpointer *p){
			p2 = p;
		}
	private:
		int *p;
		myintpointer *p2;
};

int main(){
	myintpointer a = new int;
	myintpointer b, c;
	*a = 1000;
	c = b;
	b = a;
	cout << *a << " " << *b << endl;
	delete a;
	c = new int(2000);
	b = c;
	cout << *c << " " << *b << endl;
	return 0;
}

I hope it helps.

Originally Posted by laserlight

What do you mean? Your original suggestion seems pretty clear, just that it has a limitation that might not be relevant. (And it shares with Raigne's original code the disadvantage of having to do manual memory management.)

I mean if that shall work when b and c are bound to another pointer, this is the only way I can find.

It has no other meanings. And because English is not my native language; if there are something I misunderstand, I say sorry for that.