Question

In brief, my question is about member variables as pointers in unmanaged C++.

In java or c#, we have “advanced pointer”. In fact, we can’t aware the “pointer” in them. We usually initialize the member of a class like this:

member = new Member();

or

member = null;

But in c++, it becomes more confusing. I have seen many styles: using new, or leave the member variable in stack.

In my point of view, using boost::shared_ptr seems friendly, but in boost itself source code there are news everywhere. It’s the matter of efficiency，isn’t it?

Is there a guildline like “try your best to avoid new” or something?

EDIT

I realize it’s not proper to say “leave them in stack”, here’s a more proper way to say: when i need an object to be my member variable, should i prefer a object than a object*?

Answer 1

The Boost source code is not a good example for how you should write your source code. The Boost libraries are designed to wrap up all the tedious, difficult, and error-prone code so that you don’t have to worry about it in your code.

Your best bet is to follow two general rules in your code:

• Don’t use pointers where you don’t need to use pointers
• Where you do need to use pointers, use smart pointers (like shared_ptr or scoped_ptr)