[boost] Re: (Named) Parameter Library

From: David Abrahams (dave_at_[hidden])
Date: 2005-05-09 10:47:39

Cromwell Enage wrote:
> Daniel Wallin wrote:
>> Yes, that's correct. Although the code has been
> moved
>> to the Boost CVS and the namespace has been changed
>> to 'parameter'.
> 
> Oh, that's where it is, now.  Cool!
> 
> A second look at the new code revealed that much of
> the type-extraction functionality I sought has already
> been implemented in
> <boost/parameter/aux_/arg_list.hpp>, under the nested
> struct 'key_value_type' (lines 71-78 and 186-196). 
> However, this struct is defined only for older
> compilers.  Can the definitions be moved out of the
> conditional macro blocks?  That way, a type-extraction
> metafunction like the following would work:
> 
> template < class ArgList, class KW, class Default >
> struct get_key_value_type
>   : mpl::apply2<
>         typename ArgList::key_value_type
>       , KW
>       , Default
>     >
> {
> }

This is now done; it's called index_result.  But please see (and comment
on) my recent post about rvalues, which is a closely related issue.

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