title: Access member field with same name as local variable (or argument)
body: <p>Consider following code snippet:</p>
  
  <pre><code>struct S
  {
     S( const int a ) 
     { 
        this-&gt;a = a; // option 1
        S::a = a; // option 2
     }
     int a;
  };
  </code></pre>
  
  <p>Is option 1 is equivalent to option 2? Are there cases when one form is better than another? Which clause of standard describes these options?</p>