fun with mixins

[Chad J]

Here's the jist of the attached source:

template doSomething()
{
   auto dummy = value = some + expression;
}

uint func( uint some, uint expression )
{
   uint value = 52;
   mixin doSomething!();
   return value;
}

It seems pretty hackish to me, yet useful.

Attached is a really long-winded alpha blending routine.  The advantage 
is that it's perhaps the most generalized alpha blending routine I've 
ever written that is still decently fast (yeah, could be a lot better 
with simd, gpu usage, or <insert common optimization that doesn't work 
in general on my pda>).  It could soon do things totally unrelated to 
alpha blending.  It seems kinda like something that the C preprocessor 
would be used for, though the thought of using C kinda scares me, and I 
have hope that D templates/mixins are up to the job.  Maybe someday when 
I have a lot of time on my hands I can figure out how to make the 
templates generate runtime for-loops, complete with custom-tailored 
innerloop code, which would make it a lot easier to optimize edge cases 
like sourcePixel[i+1] where there may or may not be an i+1'th pixel and 
I don't want to afford an 'if'.

I have to wonder, has someone done this stuff already (the mixin trick, 
or some sort of graphics routine framework in D)?
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: alphablend.d
URL: <http://lists.puremagic.com/pipermail/digitalmars-d/attachments/20070126/197b464c/attachment.ksh>