Unicode handling comparison

[Jakob Ovrum]

On Thursday, 28 November 2013 at 09:02:12 UTC, Walter Bright 
wrote:
> Sadly, std.array is determined to decode (i.e. convert to 
> dchar[]) all your strings when they are used as ranges. This 
> means that all algorithms on strings will be crippled as far as 
> performance goes.
>
> http://dlang.org/glossary.html#narrow strings
>
> Very, very few operations on strings need decoding. The 
> decoding should have gone into a separate layer.

Decoding by default means that algorithms can work reasonably 
with strings without being designed specifically for strings. The 
algorithms can then later be specialized for narrow strings, 
which I believe is happening for a few algorithms in 
std.algorithm like substring search.

Decoding is still available as a separate layer through std.utf, 
when more control over decoding is required.