title: Eclipse C++ "Nothing to build" error
body: <p>I've been having a "nothing to build error" working with C++ in Eclipse. I have been unable to even get a simple "hello world" program, in a project named "hw," to run:</p>
  
  <pre><code>#include &lt;iostream&gt;
  using namespace std;
  
  int main()
  {
  cout &lt;&lt; "!!!Hello World!!!" &lt;&lt; endl; // prints !!!Hello World!!!
  return 0;
  }
  </code></pre>
  
  <p>What is this "nothing to build" error? What does it mean? Why is it occurring? How do I fix it? I have checked what few leads I could find both here and elsewhere, but have thus far found nothing to help.</p>