[Boost-users] Re: C++ Template Metaprogramming - Exercise 3-6

From: David Abrahams (dave_at_[hidden])
Date: 2005-03-14 09:50:12

"Edward Diener" <eddielee_at_[hidden]> writes:

> David Abrahams wrote:
>> "Edward Diener" <eddielee_at_[hidden]> writes:
>>
>> <snip entire quoted message>
>>
>>>> When I first realized this, I was thinking about bumping up
>>>> BOOST_MPL_LIMIT_METAFUNCTION_ARITY internally, so that, in fact,
>>>> the maximum supported arity of placeholder expressions (but not
>>>> everything else) would be BOOST_MPL_LIMIT_METAFUNCTION_ARITY + 1,
>>>> but unfortunately never got to it. I'll consider fixing this for
>>>> 1.33.
>>>>
>>>> Thanks for your feedback,
>>>
>>> Why not have the answers to the exercises in the book on-line so that
>>> readers can look at them to further learn the library ?
>>
>> Someone has to write up the answers in a suitable form.  That could
>> amount to a lot of work, and we were about at our limit with finishing
>> the book.  People have volunteered to do that for other books.  Maybe
>> you'd like to take up the challenge? ;-)
>
> I am a beginner trying to learn the MPL, and therefore not qualified
> to offer answers to your exercises. 

You could try to answer them as you go through the book; it's surely a
good way to learn the material.  We'll be happy to try to point you in
the right direction if you get stuck.

> I am surprised that when you wrote the exercises you did not have at
> least theoretically correct or optimum answers written down
> somewhere, even in brief form.

We and our reviewers checked them over to make sure we knew how the
exercises might be solved, but we don't have anything written down
that's suitable for public presentation.

> But being that appears to be the case, hopefully someone else,
> experienced in MPL, will take up the challenge of providing an
> answer book, perhaps in on-line form, to your exercises.

It doesn't seem too likely to me; after all those people don't need
the answers.  Wouldn't it be a much more rewarding experience for
someone who was still trying to learn the material?

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