Re: boost:shared_ptr<> exception in checked_delete(..)

8 Sep 2002

      --- In Boost-Users@y..., "Julia Donawald"  
wrote:
...
Hi,
the folllowing works not too:
#include <vector>
#include 
class Foo
{
public:
 Foo()
 {
 };
 virtual ~Foo()
 {
 };
};
class Double_Foo
{
 public:
     Double_Foo()
     {
     };
     Double_Foo(Foo* pFoo1, Foo* pFoo2) : m_Foo1(pFoo1), m_Foo2
(pFoo2)
     {
     };
     virtual ~Double_Foo()
     {
     };
protected:
     typedef boost::shared_ptr<Foo> FooDataPtr;
FooDataPtr m_Foo1;
     FooDataPtr m_Foo2;
};
int main()
{
     Foo* pFoo = new Foo();
Double_Foo DoubFoo(pFoo, pFoo);
return 0;
}
I got the same error as in my former post. I read a bit about 
shared_ptr.
Maybe it has something to do with a cyclic, but I thought in 
anohter case of
cyclic data, namely if I have an object A which points to B and B 
holds a
member which points back to A.... that's in my case not?
If it has something to do with cyclic data then how can I solve it 
with
weak_ptr?
Thanks in advance
Julia
In both your examples you are getting in the same trouble related to 
the fact that you managed to make the same memory mnaged by 2 
independent shared_ptr. So it's obvous that when you try to free 
memory second time yuo are getting some kind of alarm, depend on 
compiler. May be in a form of exception. You should always make sure 
that memory is managed by the only smart_ptr. In this case this 
would mean hat your code should look like this:

int main()
{
     boost::shared_ptr<Foo> pFoo = new Foo();

     Double_Foo DoubFoo(pFoo, pFoo);

     return 0;
}

And DoubFoo should be changed to accept shared_ptrs ( or const 
references ) instead of raw pointers.

Regards,

Gennadiy.

Re: boost:shared_ptr<> exception in checked_delete(..)

rogeeff