Stefan Monnier <monnier@iro.umontreal.ca> schrieb am Sa., 8. Apr. 2017 um
19:58 Uhr:

> > It's not trying hard, just a simple check for a known, small, and
> > rarely-changing list of primitive symbols.
>
> To me, that's working very hard:
> - extra code.
>

Only a tiny bit.


> - extra maintenance
>

Negligible, because we rarely add new primitive types. A comment should be
added to Ftype_of to also modify a static list of primitive types when
adding a new type, but that should be it.


> - extra run-time checks.
>

Minor concern. Emacs Lisp isn't C; we prefer to help the user over saving a
couple of clock cycles.


> - no benefit since this doesn't catch a common situation.
>

Catching uncommon situation is precisely the point of precondition
checking.