Re: Deleting Vectors that Point to the Same Objects

From:

saurabh gupta <saurabhgupta1403@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Thu, 7 Jan 2010 22:41:20 -0800 (PST)

Message-ID:

<44b87a51-ff69-43a9-8855-595584975e25@u41g2000yqe.googlegroups.com>

On Jan 7, 12:32 am, James Kanze <james.ka...@gmail.com> wrote:

On Jan 5, 5:55 am, Mike <westplas...@gmail.com> wrote:

I have a class that looks like the following:
class Foo {
public:
        Foo();
        ~Foo() {} // Destructor is defined.
...
private:
        std::vector<Bar*> _list1;
        std::vector<Bar*> _list2;
...
};
As my program runs, _list1 and _list2 are populated as follows:
Bar* bar = new Bar();
_list1.push_back(bar);
_list2.push_back(bar);
In general, _list2 is a subset of _list1, so it isn't redundant.
My question is, what do I need to put in the destructor of Foo
to correctly delete these vectors? When Foo is deleted, I
want all the Bars contained in the two vectors to be deleted
as well.

Even if list2 is not a pure subset of list1, you can do this.
Iterate over the list1 pointers, remove the same pointer value from
list2 if it exists and then delete the pointer. After this, delete all
the pointers left in list2.