http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57588
--- Comment #3 from Matt Clarkson <mattyclarkson at gmail dot com> --- Thanks for that link, its very informative :) I can see why it fails to link now. About the private destructor, I'd expect it to not compile, but it does. I actually didn't even realise I'd made it private as I was just hacking together a quick testcase. Is that a bug?