g++
There are some issues with this compiler (reference ) which make it unusable under certain circumstances. The genuine Xcode compiler seems to be a be a better choice.
To install a true g++ compiler, version 4.9 for example, using MacPorts :
sudo port install gcc49
,sudo install gcc_select
(don't know if this is really needed),port select --list gcc
(to display available versions),sudo port select gcc mp-gcc49
(mp-gcc49
picked from above listing).