mizvekov added a comment. In D99005#2818606 <https://reviews.llvm.org/D99005#2818606>, @sberg wrote:
> (In a build prior to > https://reviews.llvm.org/rGc60dd3b2626a4d9eefd9f82f9a406b0d28d3fd72 "Revert > '[clang] NRVO: Improvements and handling of more cases.'") I see the > following (reduced from > https://git.libreoffice.org/core/+/649313625b94e6b879848fc19b607b74375100bf/o3tl/qa/compile-temporary.cxx) > started to fail under `-std=c++2b` with this change (and continues to > compile fine with `-std=c++20`): > It is not clear to me whether that is an intended change in behavior > according to > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2266r1.html "Simpler > implicit move", or whether it is a bug in this implementation. Yeah that one is intentional, under P2266 <https://reviews.llvm.org/P2266> as far as implicit move is concerned, that code behaves similarly to this code under C++20 (which is diagnosed for the same reason): template <typename T> constexpr T& temporary(T&& x) { return static_cast<T&&>(x); } If you want this semantics with P2266 <https://reviews.llvm.org/P2266>, you could write: template <typename T> constexpr T& temporary(T&& x) { return static_cast<T&>(x); } And the above also works on C++20. Thank you for reporting this, it's the kind of feedback we needed about real world usage of code that would break under these new rules. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D99005/new/ https://reviews.llvm.org/D99005 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
