Appender is ... slow

[Philippe Sigaud via Digitalmars-d-learn]

Well, I created a wrapper around a std.array.uninitializedArray 
call, to manage the interface I need (queue behavior: pushing at 
the end, popping at the beginning). When hitting the end of the 
current array, it either reuse the current buffer or create a new 
one, depending of the remaining capacity.

On the 'synthetic' benchmarks, it performs quite reasonably: half 
the time of  Array or Appender (twice faster), 5x faster than 
standard array, and 3-4x slower than uninitializedArray.

And... It does not change the timings in my code, it even makes 
things slower when pre-allocating to much. Only by pre-allocating 
only a few elements do I get back the original timings.

So, I guess I'm suffering from a bad case of premature 
optimization :)

I thought that, having lots of concatenation in my code, that'd 
be a bottleneck. But it appears than pre-allocation does not give 
me any speed-up.

Well, at least it got me thinking, testing LDC a bit more and 
learning things on Array and Appender ;)

Thank for your help guys, it's now time for the -profile switch 
again...