Why can I not use $this as a lexical variable in PHP 5.5.4?

Question

$ php --version
PHP 5.5.4 (cli) (built: Sep 19 2013 17:10:06) 
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies
         


        

Answer 1

It may be a bug, but there is no sense in explicit binding $this to a function anyway as it is automatically bound:

PHP documentation says

As of PHP 5.4.0, when declared in the context of a class, the current class is automatically bound to it, making $this available inside of the function's scope.

Thus, fatal error is thrown in today's version of PHP:

From PHP 7.1, these variables must not include superglobals, $this, or variables with the same name as a parameter.