Re: [boost] Re: is_convertible: bug or missing feature?

From: Thomas Witt (witt_at_[hidden])
Date: 2002-05-10 06:19:35

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On Friday 10 May 2002 12:37, John Maddock wrote:
> Yes, is_convertible only detects whether a type is *declared* as being
> convertible from one type to another: and in this case it is isn't it?  It
> does not consider whether the implementation of the conversion contains
> legal code.  Consider what would happen if template class A were declared
> as exported - in this case is_convertible would only have access to the
> declaration of the template and not the implementation in any case.
> Alternatively those compilers that instantiate templates at link time would
> also necessarily ignore the conversion implementation, and look only at the
> declaration.  IMO is_convertible is doing the right thing.

I was not argueing whether it does the right thing. Yes technically it does 
the right thing. What makes me feel uncomfortable is that it does not play 
nice with a common idiom, templated forwarding functions, in this case 
templated conversion operators.

Thomas

- -- 
Dipl.-Ing. Thomas Witt
Institut fuer Verkehrswesen, Eisenbahnbau und -betrieb, Universitaet Hannover
voice: [phone] - 4273, fax: [phone]
http://www.ive.uni-hannover.de
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