std.parallelism amap not scaling?

[JR]

On Monday, 7 October 2013 at 21:13:53 UTC, safety0ff wrote:
> I think I've found the culprit: Memory managment / GC, 
> disabling the GC caused the program to eat up all my memory.
>
> I'll have to look into this later.

 From what I've gathered from 
http://forum.dlang.org/thread/dbeliopehpsncrckdfal@forum.dlang.org, 
your use of enum makes it copy (and allocate) those variables on 
each access.

Quoth Dmitry Olshansky in that thread (with its slightly 
different context);
> And the answer is - don't use ENUM with ctRegex.
> The problem is that ctRegex returns you a pack of 
> datastructures (=arrays).
> Using them with enum makes it behave as if you pasted them as 
> array literals and these do allocate each time.

Merely replacing all occurences of enum with immutable seems to 
make a world of difference. I benched your main.d a bit on this 
laptop (also i7, so 4 real cores + HT); 
http://dpaste.dzfl.pl/a4ecc84f4

Note that inlining slows it down. I didn't verify its output, but 
if those numbers are true then ldmd2 -O -release -noboundscheck 
is a beast.