https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107532
--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:80f0052b3924569af904d1bab0858fe985f33a94 commit r13-6529-g80f0052b3924569af904d1bab0858fe985f33a94 Author: Marek Polacek <pola...@redhat.com> Date: Tue Jan 17 17:34:58 2023 -0500 c++: -Wdangling-reference with reference wrapper [PR107532] Here, -Wdangling-reference triggers where it probably shouldn't, causing some grief. The code in question uses a reference wrapper with a member function returning a reference to a subobject of a non-temporary object: const Plane & meta = fm.planes().inner(); I've tried a few approaches, e.g., checking that the member function's return type is the same as the type of the enclosing class (which is the case for member functions returning *this), but that then breaks Wdangling-reference4.C with std::optional<std::string>. This patch adjusts do_warn_dangling_reference so that we look through reference wrapper classes (meaning, has a reference member and a constructor taking the same reference type, or is std::reference_wrapper or std::ranges::ref_view) and don't warn for them, supposing that the member function returns a reference to a non-temporary object. PR c++/107532 gcc/cp/ChangeLog: * call.cc (reference_like_class_p): New. (do_warn_dangling_reference): Add new bool parameter. See through reference_like_class_p. gcc/testsuite/ChangeLog: * g++.dg/warn/Wdangling-reference8.C: New test. * g++.dg/warn/Wdangling-reference9.C: New test.
