title: MouseButtons::Left in c++/cli
body: <p>I would like to check the left button is the pressed one.</p>
  
  <p>I red on Msdna: </p>
  
  <pre><code>if(e-&gt;Button == MouseButtons.Left) {...}
  //or
  if(e-&gt;Button == ::MouseButtons.Left) {...}
  </code></pre>
  
  <p>But no one of them compiles.</p>