Subject: Re: type: (or something nil)
From: Erik Naggum <>
Date: 1998/03/07
Newsgroups: comp.lang.lisp
Message-ID: <>

* Raymond Toy
| Depends on the compiler and the code.  This bit of code:
| (defun tst (x)
|   (declare (type (or single-float null) x) (optimize (speed 3)))
|   (if x (sin x)))
| can call the C version of sin because the compiler knows that by then, 
| x must be a single-float.

  but does any particular compiler do this?

  (incidentally, C's sin is defined for double-floats.)

  God grant me serenity to accept the code I cannot change,
  courage to change the code I can, and wisdom to know the difference.