title: Why doesn't PHP support curly-brace expansion of consts in a string?
body: <p>PHP supports this:</p>
  
  <pre><code>$z = 5;
  $str = "z is $z";  // result: "z is 5"
  </code></pre>
  
  <p>and it supports this:</p>
  
  <pre><code>$c = new StdClass();
  $c-&gt;x = 9;
  $str = "x is {$c-&gt;x}";  // result: "x is 9"
  </code></pre>
  
  <p>but it does NOT support this:</p>
  
  <pre><code>class abc
  {
     const n = 2;
  }
  $str = "x is {abc::n}";  // result: "x is {abc::n}"
  </code></pre>
  
  <p>Why does PHP <strong>not</strong> support insertion of consts via the curly-brace syntax? Seems like it should...</p>