The standard Common Lisp functions are implemented in the cl
package, so you could put:
(require 'cl)
in your init file.
More precisely, cl-incf
is implemented in cl-lib
and the cl
package aliases incf
to cl-incf
.
Best practice would be for the package author to require cl-lib
and use cl-incf
; the cl-lib
forms are preferred because they're isolated in their own namespace.