Multiple inheriting class names versus single and selective include
<p>At the moment I essentially have:</p>

<pre><code>A.php:         class A { ... }
A1.php:        class A1 extends A { A1 stuff... }
A2.php:        class A2 extends A { A2 stuff... }
...
factory.php:   create($obj) {return new $obj;}
</code></pre>

<p>I'm thinking of changing it to:</p>

<pre><code>A.php:         class A { ... }
A1.php:        class B extends A { A1 stuff... }
A2.php:        class B extends A { A2 stuff... }
...
factory.php:   create($obj) { require ($obj.".php"); return new B; }
</code></pre>

<p>Any comments, or dangers that lie ahead? Only one class will ever get instantiated per PHP session.</p>
