Ubuntu install clang by default?

Question

Software testing

In general, I want to repeat the experiment https://clang.debian.net/
there is a test system and clang is installed, I
tried to do it according to the instructions
apt-get update
echo "Install of clang"
apt-get update
apt-get install --yes --no-install -recommends clang -t unstable
echo "Replace gcc, g++ & cpp by clang"
cd /usr/bin
VERSIONS="4.8 4.7 4.6"
for VERSION in $VERSIONS; do
rm g++-$VERSION gcc-$VERSION cpp-$VERSION
ln -s clang++ g++-$VERSION
ln -s clang gcc-$VERSION
ln -s clang cpp-$VERSION
done
echo "Block the installation of new gcc version"
echo "gcc-4.6 hold"|dpkg --set-selections
echo "cpp-4.6 hold"|dpkg --set-selections
echo "g++-4.6 hold"|dpkg --set-selections
echo "gcc-4.7 hold"|dpkg --set-selections
echo "cpp-4.7 hold"| dpkg --set-selections
echo "g++-4.7 hold"|dpkg --set-selections
echo "Check if gcc, g++ & cpp are actually clang"
gcc --version|grep clang > /dev/null || exit 1
but I think it's out of date
kick me in the right direction
and rebuild packages for p in `dpkg -l|egrep '^ii'|awk '{print $2}'`; do apt-get install --reinstall $p ; done