title: iostream alone gives me 457 errors
body: <p>I'm new to both C++ and Visual Studio 2015 and already have 457 errors in my first program.</p>
  
  <pre><code>    #include &lt;iostream&gt;
  
      int main()
      {
          std::cout &lt;&lt; "Hello world!" &lt;&lt; std::endl;
          return 0;
      }
  </code></pre>
  
  <p>this simple piece of "hello world" code gave me 457 errors so I started experimenting and found out that even this</p>
  
  <pre><code>    #include &lt;iostream&gt;
  </code></pre>
  
  <p>by itself gives me all those errors. I have no idea how to fix this.</p>