RE: require basic stuff from specific packages

[Drew Adams]

> > Yes, `string-trim' in in subr-x does it!
> > How are you supposed to find it tho?
> 
> In this case it's particularly egregious because sub-x.el
> isn't documented in the lisp manual or in any other manual.
> 
> Perhaps a page in the lisp manual describing these 11
> functions, saying these are potentially useful, would mean
> that someone would find them, use them and then we'd be able
> to deem them useful.

Neither the Emacs manual nor the Elisp manual documents all
commands, let alone all functions, that are useful.  (And
libraries are typically not mentioned as such.)

It's always a judgment call what to put in a manual, but there
will always be tons of functions and variables that cannot
(and in most cases should not) be documented in the manuals.

This one is essentially a utility function.  If it were
autoloaded then it would be relatively easy to discover using
completion: `C-h f string TAB'.  (And if you have a better
completion system you can also use `C-h f trim TAB'.)

If you think that a particular thing (e.g. function) should
be documented in the manual, the way to get your voice heard
is to file a bug report (aka enhancement request):
`M-x report-emacs-bug'.  Likewise, if you would like to suggest
that such a function be autoloaded.