D-Programming-Language/dmd — pull request #1829 by 9rnsr (2013-04-03 02:33:28+00:00)
Title: Issue 9773 - ref parameter with default string literal should not compile

http://d.puremagic.com/issues/show_bug.cgi?id=9773

`StringExp` will be either lvalue or rvalue, depending on its type.