On 1/3/15 7:23 PM, anonymous wrote:
For reference, here is .object.opEquals (according to documentation[1]):
bool opEquals(Object a, Object b)
{
if (a is b) return true;
if (a is null || b is null) return false;
if (typeid(a) == typeid(b)) return a.opEquals(b);
return a.opEquals(b) && b.opEquals(a);
}
I see one fundamental source of overhead: The types degenerate to
Object, resulting in virtual calls that could be avoided. Maybe it'd be
worthwhile to templatize object.opEquals: `bool opEquals(A, B)(A a, B b)`.
Good point. It's been discussed but rejected because druntime generally
shuns templates. I think that resistance is mostly vestigial by now.
Also, the typeid thing could be counter-productive with trivial
equalities. But it helps with complex ones.
By the way, I think `typeid(a) == typeid(b)` is silly. It calls
object.opEquals on the `typeid`s. And if they're not identical, that in
turn calls object.opEquals on the `typeid`s of the `typeid`s. That
fortunately hits the `is` case, or we'd go on forever. All that only to
realize that `typeid(a).opEquals(typeid(b))` suffices.
[1] http://dlang.org/operatoroverloading.html
Interesting. Is a pull request in your future? :o) -- Andrei