anonymous:
The compiler doesn't know that f's return value is unknown to
the rest of the world, because f isn't marked pure.
And, indeed, make f pure and it just works: int[] f() pure
{return [1, 2, 3];} immutable v = f();
Awesome!
"purity" seems a simple idea, but if you try to implement it
"well" in a system language as D you quickly learn that it's
composed of *many* parts. You have hit one of its many parts.
Each of those part was invented by someone, designed, implemented
(often by Hara), tested... :-)
Some small parts of D purity are not yet fully implemented, you
see part of them here:
http://d.puremagic.com/issues/buglist.cgi?quicksearch=pure
http://d.puremagic.com/issues/buglist.cgi?quicksearch=purity
Bye,
bearophile
