doc: formalize non-const reference usage in C++ style guide
Split out from #23028 by request from @refack. I’ve added people who approved the other PR as reviewers on the commit. I’m also moving the tsc-agenda
label over here, assuming @refack’s objection stands.
We generally avoid using non-const references if not necessary. This formalizes this rules by writing them down in the C++ style guide.
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
documentation is changed or added -
commit message follows commit guidelines