Implicit integer casting

[Steven Schveighoffer]

On Sun, 18 Mar 2012 22:46:56 -0400, James Miller <james at aatch.net> wrote:

>>> Another thing I have noticed, is that that compared to a cast,
>>> to!<type>  is incredibly slow. Most of the time it doesn't matter, but
>>> I was doing some work with noise generation, and found that casting
>>> the floats to integers was an order of magnitude faster than using
>>> to!int.
>>
>>
>> There's a check involved, and possibly inlining doesn't make it for  
>> whatever
>> reason.
>>
>> Andrei
>
> Oh, I wasn't complaining, more just making an observation that the
> safe to!<type> is slower than an unsafe cast. Probably obvious, but
> worth mentioning nonetheless.

Given the utility of D's templates, the achievable goal should be to make  
it equivalent.  It's worth pointing out, and should be filed as a bug.

I'd bet that it was lack of inlining, possibly due to usage of enforce  
(haven't looked at the code).

-Steve