title: When is pointer to array useful?
body: <p>I can declare:</p>
  
  <p><code>int (*ap)[N];</code></p>
  
  <p>So <code>ap</code> is pointer to int array of size N. Why is this ever useful? If I pass it to function, what useful thing it can do with it that it could not do with just a normal pointer to the array's contents?</p>
  
  <p>C FAQ say:</p>
  
  <blockquote>
    <p><strong>2.12: How do I declare a pointer to an array?</strong></p>
    
    <p>Usually, you don't want to.</p>
  </blockquote>