Re: checking whether the number is NaN
On Friday, 28 December 2012 at 20:19:49 UTC, Simen Kjaeraas wrote:
On 2012-42-28 16:12, Zhenya wrote:
Hi!
Tell me please,are there any way to check whether number is
NaN?
us std.math.isNaN. But if you really don't want to:
float x = ...;
if (x != x) {
writeln( "x is NaN" );
}
I'm unsure how aggressive the optimizer is allowed to be in
cases
like this. Theoretically it could assume x is always equal to x,
but I'd think it's not allowed to for floats.
If you're wondering how a float value could compare different to
the exact same value, consider that this would otherwise be
true:
sqrt(-1) == 0/0
Thank you,understood)
It's a nice way.
Re: checking whether the number is NaN
On 2012-42-28 16:12, Zhenya wrote:
Hi!
Tell me please,are there any way to check whether number is NaN?
us std.math.isNaN. But if you really don't want to:
float x = ...;
if (x != x) {
writeln( "x is NaN" );
}
I'm unsure how aggressive the optimizer is allowed to be in cases
like this. Theoretically it could assume x is always equal to x,
but I'd think it's not allowed to for floats.
If you're wondering how a float value could compare different to
the exact same value, consider that this would otherwise be true:
sqrt(-1) == 0/0
--
Simen
Re: checking whether the number is NaN
Tell me please,are there any way to check whether number is NaN? http://dlang.org/phobos/std_math.html#isNaN pure nothrow @trusted bool isNaN(real x); Returns !=0 if e is a NaN. --- Seems like a slight documentation disagreement. Shows bool prototype but description says returns !=0
Re: checking whether the number is NaN
On Friday, 28 December 2012 at 15:59:35 UTC, bearophile wrote: Zhenya: Tell me please,are there any way to check whether number is NaN? http://dlang.org/phobos/std_math.html#isNaN Bye, bearophile Thank you!
checking whether the number is NaN
Hi! Tell me please,are there any way to check whether number is NaN?
