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First off, thank you to everyone for all your help, I really appreciate it! :)
If I have a pointer that is not null but was simply declared (and not initialized), how can i know that? How do i know it points to nothing?
If I have:
someType* n;
if ( n == 0 || n == NULL )...
It won't work because it wasn't initialized. So how do I tell that it's "empty"?
You can't know that. An uninitialized variable could have any value (including maybe 0).
You have to just always initialize your variables and you won't have this problem. Note that it only really occurs with POD types (basically built-in types like int, char, pointers, etc.). Class types will have their default constructor called if you don't initialize them explicitly.
<groan> I hate to recommend this, but here goes...
first check for NULL, most uninitialized pointers have a value of NULL, under windows they always do. That doesnt eman you dont have a pointer that was initialized and is now invalid, thats another case.
Other than that, I think smart pointers have a method to tell if they are initialized.
What? Pointers do not have a default value of NULL. They have if they're explicitly initialized to it, which is recommended, but otherwise they are "undefined"...Quote:
Originally Posted by abachler
Yep. If I don't explicitly set it to NULL, then it's not NULL when uninitialized on windows.Quote:
Originally Posted by Elysia
How do I know if it's a "smart pointer"?
I smart pointer is a special kind of class that encapsulates the resource management of a resource. In the simple/common case that resource is a pointer that points to memory allocated with new. By choosing the right kind of smart pointer, you don't have to worry about remembering to call delete, because the smart pointer will delete the memory when it is no longer being referenced (remember that unlike Java, C++ doesn't use garbage collection and you must delete memory you allocate with new).
In fact, in good C++ you won't really need raw pointers all that often because you'll be using smart pointers or references which are generally safer.
An example of a smart pointer in standard C++ is auto_ptr, although there are others that can be more useful that aren't quite standard yet.
Or TR1's shared_ptr, weak_ptr. And maybe more?
TR1 is available for Visual Studio and... I think GCC also supports TR1?
Otherwise, boost has a smart pointer (or several) which were borrowed and included in TR1.