[dmd-beta] Struct Comparision WTF: Is the new or old behavior right?

Don Clugston dclugston at googlemail.com
Sat Dec 10 11:37:13 PST 2011

On 10 December 2011 09:11, Walter Bright <walter at digitalmars.com> wrote:
> On 12/10/2011 12:01 AM, Jonathan M Davis wrote:
>> Part of me thinks that NaN should be equal to NaN, but it's likely too
>> late
>> for that at this point, even if it were determined to be a good idea.
> That issue was decided at least 25 years ago.

The IEEE decision that x != x when x is NaN was probably the wrong
decision, but it's too late now. I think it has the effect that X.init
is dangerous. It's one of those terrible things that nearly always
works, but is broken beyond repair in the last 0.1% of cases.

Honestly, I don't get the point of X.init where by default X is
uninitialized. If it's an error to access variable x, why isn't it an
error to access x.init?

double x = x.init;
// is x initialized now?

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