Why is std.algorithm.reduce impure?

[Jonathan M Davis]

On Wednesday, March 07, 2012 17:29:24 Simen Kjærås wrote:
> On Wed, 07 Mar 2012 01:41:22 +0100, Jonathan M Davis <jmdavisProg at gmx.com>
> 
> wrote:
> > It really takes very little for something to be impure, and optimizations
> > often do it, because they end up using low-level constructs which aren't
> > pure
> > - some of which could be but aren't and others which probably can't be.
> 
> Just so this is clear - no optimization of the compiler is going to change
> the purity of a function. An optimization on the part of the programmer
> (like using appender) might, though.

I didn't say that it did, though maybe I wasn't clear enough. Optimizations of 
the _algorithms_ involved can make a function impure - such as use Appender 
instead of ~= when building arrays.

- Jonathan M Davis