On 12/12/2005 02:12 AM, Don Clugston wrote:
>> Don, since I've already done my own hack
>> (in PP_RECFLD.zip of
>> http://boost-consulting.com/vault/index.php?&directory=Template%20Metaprogramming 
>>
>> ) I was hoping to avoid this.  I'd really like something
>> that can just be done in the language itself without any preprocessing.
> 
> 
> I agree entirely. I've done enough of it too. That was just a temporary workaround.
> 
> The main need for the the hack is the absence of array literals, a feature which Walter has said is coming (but not for a while, because it's tricky to implement).

Thanks very much Don.  I've been thinking about moving to D, and
this is one more reason to do so (when the new feature is added).
However, I'm still wondering if something like mpl::fold is
possible, in particular, with placeholders (i.e. mpl::arg).
I've needed this for proto_static_disp.zip in:

  http://boost-consulting.com/vault/

in the 'Template Metaprogramming' directory.  I'd also like
to see if the policy_ptr can't be somehow incorporated into
D as a replacement for the current GC.  AFAICT, it would
involve adding to each stack frame something like the
selected_fields_description_of<FieldsVisitor, RECORD >,
defined in:

http://cvs.sourceforge.net/viewcvs.py/boost-sandbox/boost-sandbox/boost/fields_visitor/fields_visitor.hpp

where RECORD corresponds to the stack frame and FieldsVisitor
corresponds to the type of garbage collection needed.
But, of course, this is all based on smart_ptr's, which,
as pointed out in another post to this newsgroup, D doesn't
handle to well because it has no override for operator= :(

Oh well.

-best regards,
Larry