double.init is nan ..?

[Adam D. Ruppe]

On Friday, 14 March 2014 at 16:25:59 UTC, Etienne wrote:
> Struct.init is unreliable now in my books. Thanks!

Interestingly:

struct A{
         int a;
         double b;
}

void main() {
         A a;
         assert(a is A.init); // passes
         assert(a == A.init); // fails

         double test;
         assert(test is double.nan); // fails
}


I struct == other_struct works basically by checking the equality 
operator on each member inside.

So that is like saying assert(a.a == A.init.a && b.a ==B.init.b) 
which fails cuz of the nan rule.


Whereas struct is other_struct works by just comparing the memory 
bytes, regardless of the types of the contents. If they match, it 
is considered a pass, which will always be the case for comparing 
against init.