immutable bug?

[David Nadlinger]

On Sunday, 12 January 2014 at 18:09:59 UTC, Andrei Alexandrescu 
wrote:
> Put $150 on this. 
> https://www.bountysource.com/issues/1325974-type-system-breaking-caused-by-implicit-conversion-for-the-value-returned-from-pure-function

I posted a fix for this issue (i.e. the one on which the bounty 
was set).

Now tackling Manu's example, which turns out to exhibit a 
slightly different bug.

David