built-in-classbuilt-in-class, class, standard-object, t
A built-in class is a class whose instances have restricted capabilities or special representations. !!! Barrett: The rest of this looks like a duplication of text a few pages back.Attempting to use defclass to define subclasses of a built-in class signals an error of type error. Calling make-instance to create an instance of a built-in class signals an error of type error. Calling slot-value on an instance of a built-in class signals an error of type error. Redefining a built-in class or using change-class to change the class of an instance to or from a built-in class signals an error of type error. However, built-in classes can be used as parameter specializers in methods. !!! Barrett: Other ops also signal errors.
See SLOT-VALUE-METACLASSES
Any \term{class} that corresponds to a standard
\clisp\ type specified in \CLtL\
might be an instance of \typeref{built-in-class}.
The predefined Common Lisp \term{type specifiers} that are required to have
corresponding classes are listed in \figref\ClassTypeCorrespondence. It is implementation
dependent whether each of these classes is implemented as a built-in class.