On Tuesday 11 Nov 2014 21:03:56 Neil Bothwick wrote:

> Why? The compiler is not used by running software. If there was an ABI
> change meaning that mixing programs compiled with the two versions would
> cause problem, emerge -e would be prudent, but that hasn't happened for a
> long time. You don't dismantle and reassenble your car just because you
> bought a new set of spanners...

Hmmm ...  O_o

I can't recall when I rebuilt system (or was it world) because gcc changed, 
but if I were to guess I would say it was back in 2004/5.  I don't recall 
experiencing problems waiting for packages to rebuild themselves when a new 
version became available in portage.

-- 
Regards,
Mick