dchar undefined behaviour

[Anon via Digitalmars-d]

On Friday, 23 October 2015 at 21:22:38 UTC, Vladimir Panteleev 
wrote:
> That doesn't sound right. In fact, this puts into question why 
> dchar.max is at the value it is now. It might be the current 
> maximum at the current version of Unicode, but this seems like 
> a completely pointless restriction that breaks 
> forward-compatibility with future Unicode versions, meaning 
> that D programs compiled today may be unable to work with 
> Unicode text in the future because of a pointless artificial 
> limitation.

Unless UTF-16 is deprecated and completely removed from all 
systems everywhere, there is no way for Unicode Consortium to 
increase the limit beyond U+10FFFF. That limit is not arbitrary, 
but based on the technical limitations of what UTF-16 can 
actually represent. UTF-8 and UTF-32 both have room for 
expansion, but have been defined to match UTF-16's limitations.