>> The problem is the gcc package not only delivers the gcc compiler package,
>> but also some libraries. Further, gcc 4.1.x compiled programs are
>> not quite compatible with gcc 3.x compiled programs -
>> when you compile a lib with 4.x and still have 3.x compiled pgms around.
>> You really should recompile everything
>> when you update to gcc 4.1.x from 3.x.
> 
> I upgraded to 4.1.1 a couple of weeks ago & haven't done a mass recompile
> & I have yet to run into any problem: yes, there's always tomorrow (grin).

same here!


Well, but the problem that people see is, that actually the libstc++ of
gcc 4.1 _should_ be compatible with the libstdc++ of gcc 3.x - well, but
the gentoo-people are usually pessimistic about it :-)
And actually some incompatibilities are already known, i think (but they
didn't affect me *eg*)

(actually there was an ABI-switch within th gcc3.x series, before gcc
3.4 i think)