[boost] boost::any and operator ==

From: Jorge Lodos (lodos_at_[hidden])
Date: 2005-01-19 13:34:03

Hi
I needed to compare 2 boost::any values for equality, and the only reference
to this problem I found was
http://lists.boost.org/MailArchives/boost-users/msg01572.php which I think
is not correct. 
I have the following implementation working (whole file attached):
In boost::any:

bool operator==(const any & rhs) const
{
    return content ? content->clon(rhs.content) : rhs.content == 0;
}

In boost::any::placeholder:

virtual bool clon(placeholder * rhs) const = 0;

In boost::any::holder: 
virtual bool clon(placeholder * rhs) const
{
    try
    {
        if (typeid(*rhs) != typeid(*this))
            return false;
    }
    catch( bad_typeid & )
    {
        return false;
    }
    return  *static_cast<holder<ValueType> *>(rhs) == *this; 
}

bool operator==(const holder<ValueType>& rhs) const
{
    return held == rhs.held;
}

While this works, now the implementation depends on RTTI, and the template
parameter needs to know how to compare to itself. Probably an #ifdef should 
be used in the new code to maintain compatibility. Please criticize this
code, and offer any suggestion you may have. I'm willing to do some work if
needed (docs?) in order to get equality checking added to boost::any.
Thank you for boost :-)

Best regards
Jorge   

-----Original Message-----
From: boost-bounces_at_[hidden] [mailto:boost-bounces_at_[hidden]]
On Behalf Of Vladimir Pozdyayev
Sent: Wednesday, January 19, 2005 2:10 AM
To: boost_at_[hidden]
Subject: Re: [boost] Re: mail problems

David Abrahams wrote:

DA> It sounds like a problem on your end.  Am I missing something?

Well, maybe the right question should be like "is that fixable on the
boost side?"... The point is, up to this moment only boost have had
problem with that address. And mail.ru support claims they never
throw incoming mail away without notification... 's not that I
received one.

Ah, it's all well that ends well :) .

Rene Rivera wrote:

RR> The only thing I could do was to activate the vault account. Although
RR> the email verification for the vault is working again, the OP must have
RR> gotten it before I fixed that yesterday.

Thanks.

-- 
Best regards,
Vladimir Pozdyayev.
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