clang++: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/clang++ - from package: clang

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/clang++ - from package: clang
/usr/lib/llvm-3.4/bin/clang++ - from package: clang-3.4
/usr/lib/llvm-3.5/bin/clang++ - from package: clang-3.5

You may install the required package with command apt-get install {package}

Error in other languages:
clang++: bevel nie gevind nie
clang++: comandă negăsită
clang++: comando não encontrado
clang++: commande introuvable
clang++: command not found
clang++: käsku ei ole
clang++: không tìm thấy lệnh
clang++: komanda nerasta
clang++: Kommando nicht gefunden.
clang++: kommandot finns inte
clang++: komut yok
clang++: nie znaleziono polecenia
clang++: níor aimsíodh an t-ordú
clang++: no se encontró la orden
clang++: no s'ha trobat l'ordre
clang++: opdracht niet gevonden
clang++: parancs nem található
clang++: perintah tidak ditemukan
clang++: príkaz nenájdený
clang++: příkaz nenalezen
clang++: команда не найдена
clang++: командата не е открита
clang++: 命令找不到
clang++: コマンドが見つかりません