Re: [boost] type traits proposal

From: Daniel Frey (daniel.frey_at_[hidden])
Date: 2003-02-21 11:12:15

John Maddock wrote:
> 
> Those of you that have been discussing the type traits library recently
> might be interested in: http://www.regex.fsnet.co.uk/n1424dft.htm
> 
> Which contains the latest draft of my type traits standardisation proposal,
> as ever comments are always very welcome - but please remember that there is
> only a week before this has to be submitted for the pre-Oxford mailing.

Looks very good, especially given the fact that compile-failures are
replaced by returning the unmodified type (IIUC :) One thing that may
lead to a slight problem is in the last part:

"If there is no means by which the implentation can differentiate
between class and union types, then the class templates is_class and
is_union need not be provided."

I think it is much more useful to provide is_class and treat unions as
classes in this case. Optionally we could add 'is_class_or_union' as
most compilers are able to implement this even when they cannot provide
is_class and is_union - and it would IMHO be a shame not to have this
trait.

And for the unimportant part: Is "boolian" correct or should it be
"boolean"?

Regards, Daniel

-- 
Daniel Frey
aixigo AG - financial training, research and technology
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eMail: daniel.frey_at_[hidden], web: http://www.aixigo.de