[Development] Why can't QString use UTF-8 internally?

[Oswald Buddenhagen]

On Tue, Feb 10, 2015 at 10:58:58PM +0400, Konstantin Ritt wrote:
> Despite of what http://utf8everywhere.org/#conclusions says, UTF-16 is not
> the worst choice; it is a trade-off between the performance and the memory
> consumption in the most-common use case (spoken languages and mixed
> scripts).
> 
well, the question is whether a trade-off is actually necessary? why not
use an algorithmically efficient format (ucs4) where it matters (caches
of font rendering backends, i suppose?) and utf8 everywhere else?