Re: new module 'isfinite'

[Fred J. Tydeman]

On Wed, 24 Oct 2007 19:03:12 -0600, Eric Blake wrote:

>> Personally I agree with you that it's more convenient when isfinite
>> does not raise an exception.  But the bottom line is that portable
>> code can't assume that isfinite(sNaN) will return 0 without raising an
>> exception.
>> 
>
>I guess it boils down to a question of whether we need to make the text
>for all of the real-floating macros in <math.h> stronger in stating that
>signalling NaNs will not raise any exception when processed by the macros.

The latest document to address Signaling NaNs in C99 is:
  http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1011.htm

First off, in Standard C, there is no way to create or get a Signaling NaN.
Second off, the best that I could get the C committee to agree to on the
subject is full of 'should' and 'might', instead of 'shall' and 'shall not'.

---
Fred J. Tydeman        Tydeman Consulting
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+1 (775) 358-9748      Vice-chair of J11 (ANSI "C")
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