src/Registry/Common.php
protected function isRef(&$value, $modify = true)
    {
        $matches = null;
        $result =
            is_string($value) &&
            preg_match($this->refPattern, $value, $matches);
        if ($result && $modify) {
            $value = $matches[1];
        }

        return $result;
    }
protected function isRef(&$value, $modify = true)
    {
        $matches = null;
        $result =
            is_string($value) &&
            preg_match($this->refPattern, $value, $matches);
        if ($result && $modify) {
            $value = $matches[1];
        }

        return $result;
    }
protected function isRef ( & $ value , $ modify = true ) { $ matches = null ; $ result = is_string ( $ value ) && preg_match ( $ this -> refPattern , $ value , $ matches ) ; if ( $ result && $ modify ) { $ value = $ matches [ 1 ] ; } return $ result ; }
Validates if passed value is reference.

@param  mixed &$value
@param  bool  $modify  Flag specifying to modify $value
(to cut "~~> " prefix)

@return bool
Validates if passed value is reference .