[boost] Re: Field iterator

From: Larry Evans (cppljevans_at_[hidden])
Date: 2005-06-10 10:40:57

On 06/10/2005 09:47 AM, Tobias Schwinger wrote:
> Hello Larry,
Howdy.
> 
> sorry for the late reply.
No problem.
> 
> Larry Evans wrote:
[snip]
>> Sorry, I don't know what a @code block is; however, I've just uploaded
>> some test code to the vault in the:
> 
> 
> I meant something like:
> 
>     //! @code
>     //!   <brief example>
>     //! @endcode

OK. I've never seen (or don't remember) that type of comment.

[snip]
> Downloaded it, but didn't find the time to use it, yet.
> 
> It looks "potentially useful" and having an example rather than just 
> plain code will help a lot getting into it.

Great!  However, I think there may be a problem with some of the files
in boost/mpl/aux_/preprocessed/ being able to handle enumeration values
rather than numbers.  For example, in:

   boost/mpl/aux_/preprocessed/gcc/vector_c.hpp

I had to, by hand, replace each:

    vectorX_c< T,C0 >

where X is some number=1...SomeMaxValue, with:

    vectorX_c< T,T(C0) >

to get the program to compile when C0 is an element in an enumeration.
I'll go ahead and just upload the file to the sandbox.

User's should realize that for each class, RECORD, containing fields to
be visited, they need to have:

   SELECTED_FIELDS_DESCRIPTION_OF_RECORD(RECORD)

For example, in the uploaded file, this was:

   SELECTED_FIELDS_DESCRIPTION_OF_RECORD(record<visitable_yes>)

I mention this also because it plays a role similar, AFAICT, to managed 
c++'s __gc keyword.  I've never used managed c++; so, that's just a
guess and I'd like to hear corrections from those knowing more. OTOH,
containers, like stl's vector, need, instead to be wrapped in the 
template defined in:

   boost/fields_visitor/container_extern/single.hpp