BC break: $o= new stdclass; empty($o)

Hey,
Hi,

The reason for this behavior is that in PHP 3 and 4, objects were treated
very much like arrays (this is the main reason for redesigning the object
model for PHP 5).
I don't think that the old behavior is correct and an empty should always
return true (i.e. empty($var) should return true if the variable is NULL
and false if $var is an object).

to clarify: Maybe I was misusing PHP by doing the following:

class null {
function null() { }

function __call($name, $args) {
  throw(new NullPointerException('Method.invokation('.$name.')'));
}

function __set($name, $value) {
  throw(new NullPointerException('Property.write('.$name.')'));
}

function __get($name) {
  throw(new NullPointerException('Property.read('.$name.')'));
}

}

class registry {
public static $null;
}

registry::$null= new null();

class ClassType {

function forName($name) {
  // ... abbreviated ...
  return new ClassType($name);
}

function getConstructor() {
  if (!$this->hasConstructor()) return registry::$null;
  return $this->constructor;
}

}

$i= ClassType::forName($class)->getConstructor()->newInstance();

What I am doing here is fatal error prevention. To come to my point: The
following statement:

if (ClassType::forName($class)->getConstructor()) {
// ...
}

would now always evaluate to (bool)true. In PHP4 (where, of course, the
syntax need be a bit different) the above statement would evaluate to
(bool)false due to the "emptiness" of the null object.

I know this is kind of hacky but was a nice way of being able to have a
way of implementing a "Fatal error: Call to a member function of a
non-object"-safe "NULL" and being able to check for it using boolean
operators.

I don't think we should by default support the PHP 4 behavior because it's
just not right. What I suggest is to either break BC completely or support
the old behavior in compatibility mode.
What option do you prefer?

I saw you already committed a patch for the latter option (return 0 in
compat mode).

I'm not sure whether this affects a lot of users, and as noone has
commented on it, I guess PHP5 will get away with this break:)

I'll just have to find a workaround if you insist the PHP4 behaviour is
broken:)

• Timm