If you install macports you can install gcc select, and then choose your gcc version.
/opt/local/bin/port install gcc_select
To see your versions use
port select --list gcc
To select a version use
sudo port select --set gcc gcc40
Lzz makes ordinary C++ programming seem low-level. How many times have you neglected to update a header file after editing a source file? This is a silly mistake, yet we do it again and again. C++ forces you to type and maintain duplicate code. Why not let a program generate it for you?