As for your original point "do you need these other versions ?" ... probably not, some src packages for your distro may or may not be set up to be compiled with one or the other. 3.4 has an option change from 3.3, "-mtune=" rather than "-mcpu=". There is an ABI change with the 4.x series as well, which tends to make me a bit shy of using it
. Though i think the design goal is excellent. I will probably be waiting till 4.2 before i move their, unless the build scripts i do battle with end up winning
, that is.
But as long as it wasn't being used in contradiction to the overall system, with regards to key compiles (X, libc6) i don't think it would cause any real breaking problems. It may even be interesting to see how the different apps got on.
"gcc.gnu.org" is always a good site to look around on, if not somewhat obscure/dry, as they tend to be, along with the other gcc sites.
In my quest to become a fully fledged C++ guru in 21 days do I need these other versions?
Experimenting with the various "man" page examples can be interesting. Just putting together test runs to see just how the facility works. Data dumps, so to speak, can be quite revealing. And one just can't overlook SCI's site, including a general google for "templates", to look with any fairness at c++. But then, a person dosen't _have_ to use all the fancy facilities either. c++ is fine as just a better 'c'
good luck ...