As to GCC 4.x and modern C++ programs, I remember reading
from GCC bugzilla issues of 32-bit machines not having
enough memory to compile & link really large C++ programs
(web browsers and office suites). I.e. for building modern
C++, you may in worst case need even several GBs of RAM,
at least several hundreds MBs of RAM. I think some of the packages
are ignored in smaller Debian ports (like m68k) also for
this reason...