Re: [boost] Re: RE: Re: Re: Re: is_class

From: David Abrahams (dave_at_[hidden])
Date: 2003-02-16 17:40:14

Daniel Frey <d.frey_at_[hidden]> writes:

>> I agree.  You'd have to be willing to use #ifdefs, though.

No reply to that?

>> Just when I thought we were getting somewhere!
>
> My language was (again) choosen bad, sorry. I think we *are* getting
> somewhere. :)

Whew!

>>> it seems that I have a different view about software development than
>>> the authorities here.
>> 
>> Where is the fundamental disagreement?  It seems as though you're
>> willing to use #ifdefs, since that's pretty much the only way to have a
>> workaround implementation, and you seem to have accepted the idea that
>> one may be neccessary. Therefore, you can easily make patches which
>> enable a "real" implementation for compilers you can test (or reasonably
>> assume will work -- i.e. other EDG compilers with the same
>> __EDG_VERSION), and other people can see if they can also use your
>> implementation on other compilers; we can keep the codebase functional
>> and still improve its cleanliness; everyone will be happy.  I just don't
>> get what we're arguing about.

No answer for that?

> I just had another thought: *If* the workaround has no drawbacks, why
> don't we remove the "real" implementation? Why was it provided? Maybe this
> is a fundamental point, too. There "should" be a drawback, otherwise the
> workaround is already the clean one-size-fits-all code I am looking
> for.

Unless it has more #include dependencies than it needs for a
conforming compiler, or instantiates a lot more templates than it
needs to for a conforming compiler and thus compiles slower, or... is
just damn hard to understand.

> The existence and some comments in the code just give me the feeling
> that this is not the case. As an example, look at is_enum and the
> comment from dwa (Darryl?). 

That's me.  I think the problem is that otherwise is_convertible gets
instantiated on the type, and at the time the comment was written we
couldn't instantiate is_convertible on noncopyable types because it
required an accessible copy ctor.  I think we have a new version of
is_convertible which doesn't require that, so the test may be obsolete.

>> Well, let me be clear about this at least: at no point in this
>> conversation was I intending to post "as an authority."
>
> I haven't meant it in any negative way. See it in the context of Genny's
> post. It's just that someone (the "authorities") have to make decisions
> and I'm fine with this. Although I have CVS write access, I will not just
> change stuff without the OK from someone who can give an OK.

As far as this library is concerned, John is the maintainer and the
final authority.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com