You have mostly 2 choices :
1. switching to ArchLinux…
2. jump into the futur with something like (for example to get gcc-7 on Ubuntu 17.04)
cd /etc/apt
sudo cp /etc/apt/sources.list /etc/apt/sources.list_bak
sudo sed -i -- 's/yakkety/artful/g' sources.list
sudo apt-get update
sudo apt-get install -qq gcc-7 g++-7
sudo cp /etc/apt/sources.list_bak /etc/apt/sources.list
sudo apt-get update
I’ll use 1. soon, but using 2. in the meanwhile…