Re: [boost] [cpo-proposal] presentation of the idea

13 Aug 2013

      On 08/13/13 13:25, Larry Evans wrote:
...
On 08/13/13 11:35, Klaim - Joël Lamotte wrote:> On Tue, Aug 13, 2013 at
2:42 PM, Larry Evans wrote:
...
...
What if the class hierarchy is used to model a graph that
contains cycles.  For example, something like a spirit grammar
where a non-terminal on the rhs of a non-terminals definition?
Wouldn't this require some sort of smart pointer or other
garbage collection method with the ability to collect cycles?
My understanding of the proposed container is that it's mostly like having
a collection
of vectors, one for each final types, but exposing only one base interface
in container interface.
If I'm correct, I don't see how the problem you describe might be a
problem.
...
To be clear, you're saying it was not Santiago's intention to use
this libray to create something like this class:
class base_container : public base
{
public:
  virtual int do_something(int a) const;
  classifier collection;
};
Rereading the OP, I see:

collection.insert( derived_A(21) );

which means a completely new object is created during the insert; hence,
no cycles in pointer graph can occur.

Sorry for noise.