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

Subject: Re: [boost] [cpo-proposal] presentation of the idea
From: Larry Evans (cppljevans_at_[hidden])
Date: 2013-08-13 14:54:09

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 <cppljevans_at_[hidden]>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<base, std::allocator> 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.