Can you shrink it further?

[Stefan Koch via Digitalmars-d]

On Tuesday, 11 October 2016 at 07:30:26 UTC, Matthias Bentrup 
wrote:
>
> A branch-free version:
>
> void popFront4(ref char[] s) @trusted pure nothrow {
>   immutable c = s[0];
>   uint char_length = 1 + (c >= 192) + (c >= 240) + (c >= 248);
>   s = s.ptr[char_length .. s.length];
> }
>
> Theoretically the char_length could be computed with three sub 
> and addc instructions, but no compiler is smart enough to 
> detect that.

You still need to special case c < 128
as well as the follow chars.

also smaller c's are more common the bigger ones making the 
branching version faster on average.