C++ script with bash part output "hello " and C++ part output "world"

hello_world.cpp

#!/bin/bash

exc=/tmp/`basename $0`
if [ $0 -nt $exc ]; then sed -n "/^\/\*\*$/,\$p" $0 | g++ -x c++ - -o $exc; fi

echo -n "hello "
$exc

exit
/**
*/
#include <iostream>

int main()
{
  std::cout << "world" << std::endl;
}

$ ./hello_world.cpp 
hello world
$