"Optional" dependencies

Right now, there's no way to register an optional dependency for a PEAR package (i.e. a dependency that may not be required but can be utilized). An example is the Net_SMTP package using the Auth_SASL authentication routines if they are available (or, more correctly, disabling certain routines if it's not available): if ((@include_once 'Auth/SASL.php') === false) { /* Disable functions */ } Currently, there's no standard way to inform the user that having the Auth_SASL package installed will enhance the Net_SMTP package's capabilities. Thoughts on this? -- Jon Parise (jon@php.net) :: The PHP Project (http://www.php.net/)