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From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.std.c
Subject: Re: Questions about NCEG
Message-ID: <13047@smoke.BRL.MIL>
Date: 4 Jun 90 16:38:39 GMT
References: <1990May31.223436.23066@twinsun.com> <13039@smoke.BRL.MIL> <KINGDON.90Jun3221716@pogo.ai.mit.edu>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 12

In article <KINGDON.90Jun3221716@pogo.ai.mit.edu> kingdon@pogo.ai.mit.edu (Jim Kingdon) writes:
>    No, any use of NaNs and Infinities lies in the realm of undefined or
>    implementation-defined behavior, and thus is not constrained by the
>    C standard.
>Unless I'm misreading something, in the "C" locale, ...

I think you're reading the standard correctly.
My point was that "reading back in" a NaN or Infinity is beyond the
scope of the standard, because "writing it out" is beyond the scope.
It is true that "NaN" would not be an appropriate way to externally
represent a NaN, because of the argument you gave (strtod is well-
defined as not parsing those characters as a number).