Why no anonymous class and other?

[Yarco]

There exists anonymous function, and you could also use a variable to
contain such function. But why no class?
I mean, you could do:

$func = create_function('$a', 'print $a;');
$func();

or

function test($a)
{
print $a;
}
$func = 'test';
call_user_func($func, xx);

But there is no:
$class = create_class('', '');
or
$class = 'MyClass';
class $class {}

Why?

[Yarco]

Sorry, I paste wrong forum?
Could someone move it to comp.lang.php?
Yarco

There exists anonymous function, and you could also use a variable to
contain such function. But why no class?
I mean, you could do:

$func = create_function('$a', 'print $a;');
$func();

or

function test($a)
{
print $a;
}
$func = 'test';
call_user_func($func, xx);

But there is no:
$class = create_class('', '');
or
$class = 'MyClass';
class $class {}

Why?