Array!T and find are slow

[Kapps via Digitalmars-d-learn]

On Wednesday, 14 May 2014 at 23:50:34 UTC, Meta wrote:
> On the topic of lazy, why *is* it so slow, exactly? I thought 
> it was just shorthand for taking a function that evaluates the 
> expression, and wrapping said expression in that function at 
> the call site. That is, I thought that:
>
> int doSomething(lazy int n)
> {
>     return n();
> }
>
> Was more or less equivalent to:
>
> int doSomething(int function(int) n)
> {
>     return n();
> }

It's more equivalent to:

int doSomething(int delegate(int) n)
{
     return n();
}

And (I could be very likely wrong here), I believe that it's 
expensive because it's not scope and possibly requires a closure. 
Again, very likely may be wrong.