title: What is this operator< syntax?
body: <p>I saw the following code:</p>
  
  <pre><code>struct Point
  {
      int x,y;
      bool operator &lt;(const Point &amp;p) const {
          return x&lt;p.x||(x==p.x&amp;&amp;y&lt;p.y);
      }
  };
  </code></pre>
  
  <p>I don't understand what this thing is:</p>
  
  <pre><code> bool operator &lt;(const Point &amp;p) const {
        return x&lt;p.x||(x==p.x&amp;&amp;y&lt;p.y);
   } 
  </code></pre>
  
  <p>What is it?</p>