D-Programming-Language/phobos — pull request #1356 by irritate (2013-06-20 05:38:40+00:00)
Title: Issue 9636 - Allow null as a default value for Nullable function paramet...

...ers.

Also support assigning null to a Nullable as a nicety.

http://d.puremagic.com/issues/show_bug.cgi?id=9636