RE: [boost] Math constants: Inclusion requirements

From: Paul A. Bristow (boost_at_[hidden])
Date: 2001-11-01 13:05:16

> -----Original Message-----
> From: Ed Brey [mailto:edbrey_at_[hidden]]
> Sent: Tuesday, October 30, 2001 6:18 PM
> To: boost_at_[hidden]
> Subject: Re: [boost] Math constants: Inclusion requirements
>
>
> From: "Paul A. Bristow" <boost_at_[hidden]>
> > In general I agree with this, however the whole point is to ensure
> > that NO compilers don't make any difference to the calculated value,
> > so NO compiler is suitable as a benchmark - these values ARE
> the benchmark!
>
> Cleaning up for compilers with poor QoI goes beyond the charter I
> had in mind of the constants library.  Rather, I think the
> central thrust of the library should be to complement good
> compilers by providing users the basic tools they need to write
> math-based code productively.

Agreed - but you have clearly not met the 'computer validation' requirements
which have infested highly regulated industries such as food and
pharmaceuticals.

Having a single definition IS important because it deters
the validators, generally not very knowledgeable,
from worrying about about compiler QoI.

two_pi is just as much a constant as pi.
Once two_pi is calculated, there is an end to it.
(And most use of pi (apart from area) is probably two_pi rather than pi!)

Paul

Dr Paul A Bristow, hetp Chromatography
Prizet Farmhouse
Kendal, Cumbria
LA8 8AB      UK
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