Calls to struct methods and immutable

[bearophile]

Joseph Rushton Wakeling:

> Alas, pure isn't an option, because the makeFoo involves some 
> random procedures :-(

http://d.puremagic.com/issues/show_bug.cgi?id=5249
:-)

(But I have to remove its assignment to Andrei, I think I did 
that by mistake, I didn't know how such things work).

Bye,
bearophile