"Immanuel Scholz" <digital-mars@kutzsche.net> wrote in message news:a62lfc$2top$1@digitaldaemon.com...
> I am new to the list, maybe this was answered before.. (sorry, but google seems not to index digitalmars-newsserver?)

I've sent google email about that, but so far no reply.

> Why this:
> double a = double.nan;
> double b = 1.0;
> if (a == b)
>     assert (a != b);    // assertion failed.. very strange thing, I
think...
> Maybe to throw some kind of arethmetic_exception in case of comparing nan-doubles instead of this very strange double-!= behaviour?

It does it that way because that's the way IEEE 754 specifies the behavior of floating point ops. This has been adopted by C99. Changing it in D would subtly and very obscurely break code. Some things it's just too hard to swim upstream against <g>.