Re: master 37889523278: Add new `swap` macro and use it

["Mattias Engdegård" <mattias.engdegard@gmail.com>]

13 jan. 2024 kl. 10.14 skrev Eli Zaretskii <eliz@gnu.org>:

>>> Regardless of portability issues, I think the macro should be called
>>> SWAP, upper-case, to avoid clashes with functions.

I agree, better use upper case here. It's a convention to alert the programmer and reader that normal evaluation rules don't apply. After all, we don't want anyone thinking that

  SWAP (int, a[i++], a[j++]);

is a good idea. (Maybe we can make it work using preprocessor trickery but I'd rather not at this point.)

For that matter, we could add code to verify statically that the given type agrees with that of both arguments.

And I think that a swap macro is useful: in any body of code the probability of finding the moral equivalent of a botched swap,

  a := b;
  b := a;

approaches 1 as the code size grows.