&gt; Why would you want to do that in Common Lisp?<p>This isn&#x27;t a matter of this language or that language. Are you going to deliberately use a less efficient algorithm or a more convoluted design, just to please your language of choice? No idea about you, but, when a programming language doesn&#x27;t let me express what I want, I don&#x27;t force myself to want something else - I switch languages.<p>&gt; To be honest, I think folks imagine the wrong things when looking at CLOS. They think it&#x27;s Lisp foray into statically-typed OOP like C++. But it isn&#x27;t. Lisp stays dynamically typed.<p>I never said CLOS is Lisp&#x27;s take on static typing. I&#x27;m just offering an example of a use case for which CLOS isn&#x27;t as powerful as other existing alternatives.<p>&gt; The task you&#x27;re proposing is nonsensical &quot;in CLOS&quot;. It&#x27;s just not Lisp-y :-)<p>This doesn&#x27;t make sense. What I&#x27;m asking for is fundamental if you want generic programming to work: generic algorithms must be specializable for performance reasons, while still providing a uniform interface to users.