Strange cast error in compile-time function

[Frits van Bommel]

Stéphan Kochen wrote:
> Now it's complaining about genSingleCategoryIf. I can't seem to identify
> this with any of the earlier problems.
[snip]
> private string uintToString(uint i)
> {
>     if (i < 10)
> 	    return [cast(char) (i + '0')];
>     else
>     	return uintToString(i / 10) ~ uintToString(i % 10);
> }
> 
> private string genSingleCategoryIf(string prop, uint start, uint end)
> {
>     if (start == end)
>     {
>         return "if (c == " ~ uintToString(start) ~ ")\n" ~
>                "    return GeneralCategory." ~ prop ~ ";\n" ~
>                "else ";
>     }
>     else
>     {
>         return "if (c >= " ~ uintToString(start) ~ " && " ~
>                "c <= " ~ uintToString(end) ~ ")\n" ~
>                "    return GeneralCategory." ~ prop ~ ";\n" ~
>                "else ";
>     }
> }

DMD doesn't seem to like that call to uintToString(start) from 
genSingleCategoryIf, even though it works fine on its own. The 
workaround is simple though, just change the single-digit case to 
'return "0123456789"[i..i+1];'.