Basic Pointer Help

Hi all,

I'm having a problem in some code and I think it's because I've misunderstood how pointers are supposed to work. I've read the tutorials but perhaps I haven't understood them correctly. My aim is to post some code, explain what I think is supposed to happen and then maybe one of you lovely people could explain why it does not?

Code:

---

class MyClass
{
    public:
              int count;
              int GetCount();
              void AddOne();
}

MyClass foo;

//this should point bar to the rvalue of foo?
MyClass *bar = &foo;

//this vector now holds the object foo
vector.push_back(foo);

//this should add 1 to count inside foo because above I declared bar as a pointer to foo.  The operations that I perform on bar should be done on foo as I told bar to point to the addressof foo

bar->AddOne();


for(int i = 0; i < vector.size(); i++)
{
  //I want this to call foo.GetCount which was updated by bar.AddOne()
  vector[i].GetCount();
}

---

Just to say that this is pseudo code to try and demonosrate the point. You can presume that AddOne actually adds one to count and vector is a correct lvalue and the like.

Does foo being inside a data structure matter to bar->AddOne()? More likely, have I got the wrong idea here?

Thanks in advance.

You should post something that will compile, not random 1-line snippets of all your ideas.

Each line you post is fine (in a context we assume), but that's not the same as the context in which you tried it (or understood it).

Your theory is correct, but I don't believe it will work. I cannot say for sure since you have not provided the declaration for your vector, though.
Remember that if you declare your vector as

std::vector<MyClass> vector;

Then, a copy of foo will be made and inserted into vector. Therefore, your action on bar (or foo) won't affect the object inside the vector.
You would need a pointer to be stored inside the vector for it to work properly.
(See smart pointers if you need to use pointers.)