Bug #73647 [Nab]: stdClass is not inherited if the class definition doesn't explicit it.

Edit report at https://bugs.php.net/bug.php?id=73647&edit=1 ID: 73647 User updated by: klaussantana at gmail dot com Reported by: klaussantana at gmail dot com Summary: stdClass is not inherited if the class definition doesn't explicit it. Status: Not a bug Type: Bug Package: Scripting Engine problem Operating System: any PHP Version: 7.0.13 Block user comment: N Private report: N New Comment: Probably I'll do this RFC. Ahh.. I can't use is_object() to typecast a parameter like this: function ( is_object($Param) ) { } Also, I can't use something like this: function ( Object $Param ) { } Or this: function ( object $Param ) { } I only can typecast objects that I explicit know the class or one of its interface names, like: function ( UserLand $Object = null ) : UserLand { return $Object; } Also, if you just typecast any other kind of value to an object, a stdClass object will be created. Looking at this behaviour, it just make sense that any user defined class should be a stdClass extension if ommited. The stdClass is not used by other built-in classes. Also it has no properties or methods, having only the magic methods defined by core that does nothing. As you said, it's an empty class. So any new class should come from this empty class if not specified an ancestor. This should permit correctly test an Object to see if it is a Standard Class (stdClass) or not. Closures, Exceptions and other non-standard classes have core limitations: like the prohibition of assigning a property to a closure object. I don't want this kind of object passed as parameter, only stdClass compatible. But classes that do not explicit it will fail parameter typecasting unless I know the class name. Previous Comments: ------------------------------------------------------------------------ [2016-12-04 08:47:33] requinix@php.net > All classes defined without the extends expression should be > implied as an > extension of stdClass. That only works if stdClass is an implied base class. It is not. UserLand and stdClass are completely and entirely unrelated classes; they have as much in common as UserLand and SplFileInfo do. If you want this as a feature request, that's fine, but a change like this would probably require an RFC. https://wiki.php.net/rfc/howto And I still don't understand why you can't just use is_object(). ------------------------------------------------------------------------ [2016-12-04 08:02:23] klaussantana at gmail dot com requinix@php.net You missed my comment right after publishing.. All classes defined without the extends expression should be implied as an extension of stdClass. The following code should produce no error, but it does: <?PHP class UserLand {} $f = function ( stdClass $Object = null ) { # I want any object here that is not built-in classes like those: Closure, Exception, PDO, etc... } $f(new UserLand); // Doesn't work as of UserLand do not explicit extends stdClass. // So it should be reasonable to UserLand pass an instanceof test against stdClass. ?> Should I change this to "Feature/Change Request" instead? ------------------------------------------------------------------------ [2016-12-03 21:37:49] requinix@php.net PHP does not have an implicit base class like C#'s System.Object or Java's java.lang.Object. stdClass is just a built-in, empty class. If you want to know whether something is an object then use is_object(). ------------------------------------------------------------------------ [2016-12-03 21:14:51] klaussantana at gmail dot com This causes a serious problem when you try something like this: <?PHP class Insecure {} ( function ( stdClass $Object = null ) { # Some stuff only for stdClass inheritants... return $Object; } ) ( new Insecure ); ------------------------------------------------------------------------ [2016-12-03 21:04:54] klaussantana at gmail dot com Description: ------------ For some reason, if you not explicit extends a class from stdClass it will not pass the instanceof test. Test script: --------------- <?PHP /**** * stdClass Inheritance Failure * ================================================================================ * * This example shows how stdClass is not inherited in classes definitions that * do not explicit it. * */ class InstableDefinition {} class StableDefinition extends stdClass {} class AnotherInstableDefinition extends InstableDefinition {} class AnotherStableDefinition extends StableDefinition {} $Objects = [ 'Instable Object' => new InstableDefinition, 'Stable Object' => new StableDefinition, 'Another Instable Object' => new AnotherInstableDefinition, 'Another Stable Object' => new AnotherStableDefinition, ]; foreach ( $Objects as $Object ) { $ObjectClass = get_class($Object); $ObjectStandard = $Object instanceof stdClass; $ObjectEvaluates = $ObjectStandard ? 'does' : "doesn't"; echo "The {$ObjectClass} class objects {$ObjectEvaluates} instance from stdClass." .PHP_EOL; } echo 'All these tests ran under PHP version ' .PHP_VERSION .'.' .PHP_EOL; Expected result: ---------------- The InstableDefinition class objects does instance from stdClass. The StableDefinition class objects does instance from stdClass. The AnotherInstableDefinition class objects does instance from stdClass. The AnotherStableDefinition class objects does instance from stdClass. All these tests ran under PHP version 7.0.13. Actual result: -------------- The InstableDefinition class objects doesn't instance from stdClass. The StableDefinition class objects does instance from stdClass. The AnotherInstableDefinition class objects doesn't instance from stdClass. The AnotherStableDefinition class objects does instance from stdClass. All these tests ran under PHP version 7.0.13. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=73647&edit=1