toUTFz and WinAPI GetTextExtentPoint32W

[Christophe Travert]

> Here is a more readable and a bit faster version on dmd windows:
> 
> size_t utfCount(string text)
> {
>      size_t n = 0;
>      for (uint i=0; i<text.length; ++i)
>           n += ((text[i]>>6)^0b10)? 1: 0;
>      return n;
> }

Nice. It is better with gdc linux 64bits too. I wanted to avoid 
conditional expressions like ?: but it's actually slightly faster that 
way.

And now people can't tell it is dangerous because it could return a 
fuzzy number.

Even faster, through less readable:

size_t utfLength(string text)
{
  size_t n=0;
  for (size_t i=0; i<text.length; ++i)
    n += (((text[i]>>6)^0b10) != 0);
  return n;
}

Let's see how we can boost std.utf.stride that way...

-- 
Christophe