[boost] Re: Optimization of MPL expression?

From: David Abrahams (dave_at_[hidden])
Date: 2003-09-13 10:52:15

"Brock Peabody" <brock.peabody_at_[hidden]> writes:

>> -----Original Message-----
>> From: boost-bounces_at_[hidden] [mailto:boost-bounces_at_[hidden]]
>> On Behalf Of Joaquín Mª López Muñoz
>> Sent: Friday, September 12, 2003 4:55 AM
>> To: Boost mailing list
>> Subject: Re: [boost] Optimization of MPL expression?
>> 
>> 
>> 
>> Brock Peabody ha escrito:
>> 
>
> [...]
>
>> I wanted to hide MPL from the user. Picture yourself a potential
>> average user reading the tutorial and, when it comes to the
>> specification of indices, being referred to the MPL documentation!
>> She'd probably be scared away. MPL is terrific, but IMHO is not a
>> library every programmer would want to be exposed to.  Besides, the
>> MPL sequence used must be a forward sequence, not every sequence is
>> valid. A lot of technical mess for such a simple application.
>
> On the surface this seems like a good argument, but I really don't
> think we want every boost library that needs typelists to roll their
> own just so the users don't have to see the MPL.  If you want to
> hide the MPL and keep the user from having to choose a container you
> could use a using declaration to bring mpl::vector in to
> indexed_sets.

Sometimes vector is the wrong name.  When building a domain-specific
language you may need to build a wrapper.  See boost/python/bases.hpp
and boost/python/detail/type_list.hpp.

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