If you want gcc's minor versions in their own slots, then you want the mutislot use flag:
:; euses multislot sys-devel/gcc:multislot - Allow for SLOTs to include minor version (3.3.4 instead of just 3.3) -JimC -- James Cloos <cl...@jhcloos.com> OpenPGP: 1024D/ED7DAEA6
