Always-true predicate?

[Lars Ingebrigtsen <larsi@gnus.org>]

Currently, Emacs has:

----
   Sometimes, when you call a functional, it is useful to supply a no-op
function as the argument.  Here are two different kinds of no-op
function:

 -- Function: identity argument
     This function returns ARGUMENT and has no side effects.

 -- Function: ignore &rest arguments
     This function ignores any ARGUMENTS and returns ‘nil’.
----

`identity' is kinda-sorta used as the opposite of `ignore' many places
where you're feeding predicates to functions, but takes only one
parameter and, of course, returns nil if you give it nil.

Would it make sense to add a function that's exactly the opposite of
`ignore' (for symmetry and convenience)?  If so, what would it be
called?

I've googled to see what other languages do.  Rust and NPM has "always",
and many more Java-inspired frameworks have "truePredicate", but this
isn't trivial to google for...

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no