Comparing floating point: == vs is

[Daniel Murphy]

"Jonathan M Davis" <jmdavisProg at gmx.com> wrote in message 
news:mailman.1705.1310853321.14074.digitalmars-d-learn at puremagic.com...
> I suspect that the problem is a combination of issues with NaN and real. 
> If I
> change the first three tests (which test init which is NaN) to is, then 
> they
> pass, but the test for real.max fails regardless of whether is or == is 
> used.
> The other tests seem to pass regardless of whether is or == is used. So, I 
> may
> need to do something special for NaN, and I may have to do something to 
> deal
> with the padding in real. I don't know.
>
> - Jonathan M Davis

They all pass for me when using 'is' on win32, so assuming you're on linux 
or osx the padding issue is what you're running into.  The workaround is 
probably using isIdentical from std.math for floating point types instead of 
'is' and only swapping the first 10 bytes in endianswap (for reals only, the 
other types should work).  The 'is' problem will be fixed, but swapping the 
full 12 or 16 bytes of real will always result in the wrong value.