title: std::string '+' : cannot add two pointers
body: <p>Why assignment </p>
  
  <pre><code>std::string s="aaa"+1
  </code></pre>
  
  <p>works fine while </p>
  
  <pre><code>std::string s="aaa"+1+"bbb" 
  </code></pre>
  
  <p>gets error <code>Error   14  error C2110: '+' : cannot add two pointers</code></p>