I've tried to compile simple hello world on Fedora 20 with Clang, and I get the following output:
d.cpp:1:10: fatal error: 'iostream' file not found
#include <iostream>
I don't have any idea how to resolve it.
This is because g++ is not installed, so libstdc++ is not present.
You can install g++, or if LLVM is preferred, install LLVM libc++ and specify that you want to use it, like so:
sudo apt-get install libc++-dev
clang++ -stdlib=libc++ <rest of arguments>
You may wish to link /usr/bin/c++ to the default compiler:
ln -s /usr/bin/c++ /usr/bin/clang++-libc++
and then compile simply using
$ c++ <args_as_usual>