Linux

gcc 5 on ubuntu 14.04
    sudo add-apt-repository ppa:ubuntu-toolchain-r/test
    sudo apt-get update
    sudo apt-get install gcc-5 g++-5    
    sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5
    https://gist.github.com/beci/2a2091f282042ed20cda