title: PHP - assign value of function to class constant
body: <p>In PHP when you define a class level constant as in:</p>
  <pre><code>const MY_CONSTANT = 'hello constant';
  </code></pre>
  <p>Why can't you initialize this value with a function such as</p>
  <pre><code>const MY_FILEPATH = dirname(dirname(__FILE__)) . '/heres-my-file.php';
  </code></pre>