bug#61730: 30.0.50; Compiler warnings for delq and delete

[Ruijie Yu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> I have some doubt about the new property's name
> "important-return-value".  It's not bad but it also doesn't really tell
> what the warnings are about.  My English is not good enough to come up
> with something better though ... "enforce-retval-passing"...hmm,
> probably not.

Maybe we can take inspirations from other langagues?  In rust we have
the `#[must_use]' attribute [1], and in C++17 and C23 we have the
`[[nodiscard]]' attribute [2] [3].

Also, is there any definitive relation between this
'important-return-value property and the existing "pure" function
declaration?  Like the `(declare (pure t))' thing in the front of a
defun.

[1]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute
[2]: https://en.cppreference.com/w/cpp/language/attributes/nodiscard
[3]: https://en.cppreference.com/w/c/language/attributes/nodiscard

-- 
Best,


RY