Re: [boost] pqs - physical quantities library

From: Terje Slettebø (tslettebo_at_[hidden])
Date: 2004-10-23 07:10:40

>From: "Andy Little" <andy_at_[hidden]>

> I have been continuing with my physical-quantities library over the last
> year,
> http://www.servocomm.freeserve.co.uk/Cpp/physical_quantity/index.html
> and I am now seeking feedback as to whether it is worth putting this
forward
> as a boost library proposal....

I'd be interested in such a library in Boost. It's also actually on the C++
standards committee's "wishlist for C++0x"
(http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2004/n1689.html):

"a SI/Units library. ( e = m c2, and end to the mars lander crashes.)"

I've been playing with a library like this, a year or so ago, too, but saw
there were several proposals in that area, which worked similarily, and
decided instead to focus on the Concept Traits library. I decided that I
could then instead support other people's proposals in the area of
quantity/units library.

I've always seen this kind of library as a "fun" thing, :) as I'm interested
in science, having "played with" electronics, physics, chemistry, etc.
especially in my youth, and I'm sure such a library - of Boost standard
(using modern C++), which this one seems to be - would be a great thing for
scientists, and people interested in science, everywhere.

I tried to test the library on Intel C++ 7.1 (electronics_example.cpp,
picked at random) but got some errors which prevented the test, so I've
tried it on g++ 3.2, instead, where it worked. Unless I haven't found it,
you might want to include which compilers/versions it works for in the docs.
If you're interested in the diagnostics from Intel C++, I can mail them to
you.

>From the examples and code I've looked at, it looks well designed and easy
to use. You've obviously put a lot of work into this, both with the library
and documentation. I also did some tests, myself, seeing how it dealt with
the computation of units, and that worked fine.

Sorry I can't give more feefback at this time - it's busy at work with long
days, these days. but I wanted to at least to chime in and say that, yes,
I'd be interested in a such a library in Boost.

What might help is to give an overview of other libraries that exist for
this, and what makes PQS different. One place to look is the Boost Files
section (I saw at least three such libraries there). I saw that Walter
Brown's library is mentioned in the docs, though.

I think you should go ahead with it, and if it comes to formal review, I'll
make sure to do an in-depth study of it, preferably some time before the
review.

Regards,

Terje