[Bug c++/28408] What should be value of complex<double>(1.0,0.0) *= -1?

bangerth at math dot tamu dot edu gcc-bugzilla@gcc.gnu.org
Thu Sep 7 02:30:00 GMT 2006

------- Comment #17 from bangerth at math dot tamu dot edu  2006-09-07 02:29 -------
Subject: Re:  What should be value of complex<double>(1.0,0.0)
 *= -1?

> If you have IEC 60559 at hand, and it explicitely says, as normative, that 0 *
> -finite = -0 then, I agree that this is a bug. However, I have yet to
> understand why F.8.2, in particular the positive statements, can be considered
> only illustrative, when the entire F is normative and there are no indications
> of that.

It is true that Appendix F has "normative" in the section title, but
F.8 starts out with
  This section identifies code transformations that might subvert IEC
  60559-specified behavior, and others that do not.
I read that as "this section is illustrative". I pretty much read F.8.2 as
a list of things to watch out for. The right hand side of the table
appears to me to be cases of where for example the transformation on the
left is not valid, but I don't think it is meant as an exhaustive list of
these cases.


Wolfgang Bangerth                email:            bangerth@math.tamu.edu
                                 www: http://www.math.tamu.edu/~bangerth/



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