CTFE: What limitations remain?

[Don]

dsimcha wrote:
> The documentation for CTFE is outdated and specifies limitations that no
> longer exist thanks to Don's massive overhaul.  For example, a big one is that
> pointers now work.  What limitations that could potentially be removed still
> do exist in CTFE as of 2.054?

The updated CTFE documentation is here:
http://d-programming-language.org/function.html