https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89780
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> --- (In reply to S. Davis Herring from comment #3) > Does this need to be language-version-dependent, given > https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1825r0.html (in > C++20) and > https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2266r3.html (in > C++23)? So far I couldn't find a testcase where we either 1) say that a std::move is pessimizing while it's only redundant, or 2) don't say that a std::move is redundant when it is, under the new rules. I don't think we fully implement p2266r3 yet, maybe once we do, the warning will have to be adjusted. For instance, this struct S1 { S1(); S1(S1 &&); }; struct S2 : S1 {}; S1 f (S2 s) { return std::move(s); } with -std=c++20 will warn about a redundant move in the return statement. In C++17 it will not compile because the deleted S1(const S1&) is used.
