[Boost-users] Re: units library

From: Andy Little (andy_at_[hidden])
Date: 2004-12-24 14:21:57

"Jonathan Turkanis" <technews_at_[hidden]> wrote in message
news:cqe4qo$hf5$1_at_sea.gmane.org...
> Dan Dimerman wrote:
>> Jeff Garland wrote:
>>> On Wed, 22 Dec 2004 15:33:18 -0700, Chris Goller wrote
>>>
>>>> I've been looking around for a unit conversion library.  I've seen
>>>> some on http://groups.yahoo.com/group/boost/files/ but am wondering
>>>> if any have been put into boost release yet.
>>>
>>>
>>> Nope, none are in a boost release.  And I think that the most active
>>> author has recently abandoned his effort :-(  So I'm afraid you
>>> shouldn't expect anything soon.
>>>
>>> Jeff
>> Are you referring to something like this:
>>
>> boost_1_32_0/libs/mpl/doc/tutorial/dimensional-analysis.html
>
> I believe he's refering to Andy Little's pqs library. Andy announced
> recently
> that he wasn't going to propose it for review, but he didn't say why. I
> never
> looked at it.

In fishing for feedback on boost devel recently:
http://aspn.activestate.com/ASPN/Mail/Message/boost/2201024

I came to the conclusion that the interest was not there.( At some point one
has to take an executive decision as to where ones time can be spent most
profitably. ) A large amount of work would be required both in converting
the implementation to integrate better with and reuse boost components and
in upgrading the documentation. Among the bones of contention in a review
would be the type deduction mechanism, which is a major part of the
library,eg a substitute  for current lack of decltype, auto typeof etc. ( I
dont think it will be possible to do units really cleanly until C++ has this
in place in the language).

However I hope I have provided One reasonably complete solution to some of
the details of the problems of units (eg the semantics of operations) That
is I believe an area that has not had so much work done ( as opposed to the
compile time dimensional analysis) as well as the useability aspect ( the
'user interface') as indicated in the afore mentioned thread , which I have
attempted to document in the public version of the library. , so I recommend
any one interested in units to take a look:

http://www.servocomm.freeserve.co.uk/Cpp/physical_quantity/index.html

The latest public download on the above site, pqs-2-00-02, has been tested
only on VC7.1 and gcc3.2 and is reported by Terje Slettebo as not compiling
on Intel C++ 7.1

regards
Andy Little