std.mixins

[Lutger]

Nick Sabalausky wrote:

> "Lutger" <lutger.blijdestijn at gmail.com> wrote in message
> news:i5jiap$rvb$1 at digitalmars.com...
>> dsimcha wrote:
>>
>> ...
>>>> My suggestion is to include a mixin for unrolling loops.
>>>
>>> I thought about this.  Simple loop unrolling doesn't seem like a very
>>> useful
>>> optimization on modern hardware because branch prediction and pipelining
>>> have
>>> gotten so good.
> 
> We shouldn't forget, D is supposed to be a systems language, so it needs to
> work well for a variety of embedded systems. We can't assume all CPUs are
> going to be just as advanced as a modern desktop CPU. Plus, as a systems
> language, we shouldn't rule out people who have a reason to optimize for
> lower-end hardware.
> 
> 
>>>It can still be useful if you also change the loop body a
>>> little, for example using multiple accumulators to increase instruction
>>> level
>>> parallelism,
>>> but this is hard to write generically.  I can't think of a way to write
>>> such a
>>> mixin such that it would be both generic and useful.
>>
>> Probably not for performance, but as a utility for metaprogramming I find
>> it
>> sometimes convenient.
> 
> Isn't performance the whole point of loop unrolling? What other use could
> there be?

I should have called it 'static foreach'