[boost] Re: Interest in smart pointer with value semantics?

From: Dan W. (danw_at_[hidden])
Date: 2004-01-05 02:41:35

David B. Held wrote:
> struct ptr_wrapper deep_const
> {
>     raw_ptr p_;
> };
> 
> Now, does deep_const go inside every class definition, and
> make those members const too?  Does it make raw_ptr a
> deep_const type when it is aggregated within ptr_wrapper?
> I mean, I see that it could probably be done, but I don't think
> I'd want to write it. ;)  And if a class were designed for shallow
> const, but got deep_const-ed via aggregation, that could have
> some suprising effects, no?  And if deep_const doesn't go
> that deep, then wrapper types like the above severely limit
> its usefulness, no?  I'm not saying it's a bad idea, necessarily.
> I'm just wondering if it solves more problems than it creates.

I must confess I haven't thought that deep-ly about it  :)

Let me see if whatever I did fancy could work:

class y;

class x
{
    y deep_const *a;
public:
    y* get_a();                         //boom!
    y const * get_a() const;            //boom!
    y deep_const * get_a() deep_const;  //ok
    y const * get_get_a() const
    {
        get_a();  //boom!
    }
    y deep_const * get_get_a() deep_const
    {
        get_a();  //ok
    }
};

Probably it's not that simple, but I don't see why it isn't at the moment...