🚀 go-pugleaf

In article <KANZE.96Jan9135752@slsvewt.lts.sel.alcatel.de>,
James Kanze US/ESC 60/3/141 #40763 <kanze@lts.sel.alcatel.de> wrote:
>In article <4ctk66$57j@lyra.csx.cam.ac.uk> nmm1@cus.cam.ac.uk (Nick
>Maclaren) writes:
>> Don't bother - the 'constants' in <float.h> aren't!  This is a specific
>> exclusion to make life easier for systems with separate floating-point
>> processors, and makes <float.h> almost useless for numerical analysts.
>
> Is this true for all of the ``constants'' in float.h, or only some of
> them?  I don't have my C standard here to check, but I thought that
> this was only true of the constants whose type was non-integral.

ANSI section 2.2.4.2.2 "Characteristics of floating types <float.h>"

#   Of the values in the <float.h> header, FLT_RADIX shall be a constant
# expression suitable for use in #if preprocessing directives; all other
# values need not be constant expressions.

Yup, that's annoying.  I can't even determine if "long double" has
more precision at compile time with "#if LDBL_MANT_DIG > DBL_MANT_DIG".
-- 
	-Colin