title: PHP Reflection: get constant's doc comment
body: <p>It is easy to retrieve the doc comment for methods and properties. But what about constants? There is no <code>ReflectionConstant</code> class which would allow me to call <code>getDocComment()</code> on them. It's possible to get the list of constants and their values as strings using <code>ReflectionClass::getConstants</code> but that's all. Is there a workaround? </p>