title: What does ~0 mean in this code?
body: <p>What's the meaning of ~0 in this code?<br>
  Can somebody analyze this code for me?</p>
  
  <pre><code>unsigned int Order(unsigned int maxPeriod = ~0) const
  {
      Point r = *this;
      unsigned int n = 0;
      while( r.x_ != 0 &amp;&amp; r.y_ != 0 )
      {
          ++n;
          r += *this;
          if ( n &gt; maxPeriod ) break;
      }
      return n;
  }
  </code></pre>