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Subject: Re: [proto] current state
From: Eric Niebler (eric_at_[hidden])
Date: 2010-12-20 11:10:39

On 12/20/2010 8:10 AM, Maxim Yanchenko wrote:
> Hi all,
> I see there going to be breaking changes in Proto and Phoenix (like "contexts
> must go", visitors etc).

I don't think there will be massive breaking changes anytime soon. I
/might/ deprecate contexts, but I doubt I could remove them. Too many
people use them. Someday I might come out with a completely different
C++0x version of Proto with significant breakages, but until then, I
think you're safe.

And I might not even deprecate contexts. A week ago I tried porting
Proto's examples from contexts to transforms and found they got
significantly more complicated. I don't have any definite plans wrt
contexts and transforms yet.

> So the question is: for a beginner who just started to learn Proto, which parts
> of Proto should be studied now and which are likely to be dropped/changed? Just
> to avoid wasting time learning something deprecated.

Despite the fact that they're simpler for some things, I'd say avoid
contexts. They won't get you as far as transforms.

> P.S. Eric, there is a bug in proto::display_expr, I wrote about it (and posted a
> patch) in comments to your "Playing with syntax" article on cpp-next, could you
> please take a look when you have time?

I just committed a fix to trunk. Thanks for bringing this to my attention.

Eric Niebler
BoostPro Computing

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