Let's take this class as example and assume that get_context() returns the source of the call:

class A {
    public function __construct( ) {    
        if( get_class( get_context( ) ) == B ) {
            return true;
        } else {
            return false;
        }    
    }
}

class B { 
    function __construct( ) {
        $a = new A( );
    }
}

$a = new B( ); // returns true, as B is the invoking class of A

$a = new A( ); // returns false, as B is invoked outside of any class

So, my questions are: 1) can a function know the context that calls it? 2) can a object know context from where it has been instantiated?

Or am I dreaming up new features not implementable in PHP?