Tips for fast string concatenation?

[monarch_dodra]

On Friday, 21 June 2013 at 10:09:10 UTC, Gary Willoughby wrote:
> Have you any tips for using D when you need fast string 
> concatenation? I regularly use code like this:
>
>     foreach (i, range)
>     {
>         foo ~= bar;
>     }
>
> or:
>
>     foo = foo ~ bar ~ baz ~ qux;
>
> I've used std.string.format(...) in some instances which sped 
> things up which surprised me.
>
> Are there faster ways of appending strings?

Regardless of whether you end up using lots of ~=, or Appender 
(possibly with formattedWrite), using reserve never hurts.