# 2.4.18 类型描述符

类型描述符（type descriptor）是一种记录(record)，其中描述了某个类型的信息。记录的第一个槽是一个符号，这个符号表示了这个新类型的名称。而type-of 函数就是从这里获得的类型的信息。余下的槽都不被 Emacs 使用；它们可以用来拓展 Lisp。

类型描述符是 cl-sreucture-class 的实例。


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