std::numeric_limits::is_iec559

[Roberto Bagnara]

Gabriel Dos Reis wrote:
> Roberto Bagnara <bagnara@cs.unipr.it> writes:
> 
> | I have always used std::numeric_limits::is_iec559 thinking that,
> | as per the C++ standard, it yielded "[t]rue if and only if the type
> | adheres to IEC 559 standard."
> | 
> | On a Mac OS X 10.4 machine with GCC 4.0.1, however, I get the value
> | true for long doubles but, as far as I can tell, the layout of
> | long doubles there does not conform to the 128-bit format specified
> | by IEC 559.
> 
> I don't follow.  Exactly in what aspect do you believe the Mac OS X
> 10.4 representation is not conformant to IEC 559?

 From your question I gather that IEC 559 does not specify a binary
format for 128-bit numbers.  If that is the case, than that is one
of the things I was missing.
Thanks,

    Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara@cs.unipr.it