org-mode babel and literate

#+title: Test of Literate Programming

#--------------------------------------------------------
#COLLECTION
#--------------------------------------------------------
#Below I have a collection of several hello world !
#I don't want to execute them neither show the source now

#+name: cpp_hello_world
#+begin_src C++ -n :exports none
  #include <iostream>

  int main(int argc, char ** argv)
  {
      std::cout << "Hello World !" << std::endl;
      std::cout << "fglkjfglk" << std::endl;
      std::cout << "dkfjdfkjdkdjfkdjfkdfjdkf" << std::endl;
      return 0;
  }
#+end_src

#+name: haskell_hello_world
#+begin_src haskell -n :exports none
[1..10]
putStrLn "Hello World !"
#+end_src

#+name: r_hello_world
#+begin_src R -n :exports none
x <- 1:5
print(x)
print("Hello World !")
#+end_src
#--------------------------------------------------------
#END COLLECTION
#--------------------------------------------------------

* Hello Word in C++
Here is the source code :
#+call: cpp_hello_world [:exports code]
and here is the result :
#+call: cpp_hello_world [:results output :exports results]

* Hello World in Haskell
Here is the source code :
#+call: haskell_hello_world [:exports code]
and here is the result :
#+call: haskell_hello_world [:results output :exports results]

* Hello World in R
Here is the source code :
#+call: r_hello_world [:exports code]
and here is the result :
#+call: r_hello_world [:results output :exports results]