https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107488
--- Comment #2 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:32a06ce38a38bf37db468f0e6c83520fcc221534 commit r13-3642-g32a06ce38a38bf37db468f0e6c83520fcc221534 Author: Marek Polacek <pola...@redhat.com> Date: Tue Nov 1 17:05:52 2022 -0400 c++: Quash -Wdangling-reference for member operator* [PR107488] -Wdangling-reference complains here: std::vector<int> v = ...; std::vector<int>::const_iterator it = v.begin(); while (it != v.end()) { const int &r = *it++; // warning } because it sees a call to __gnu_cxx::__normal_iterator<const int*, std::vector<int> >::operator* which returns a reference and its argument is a TARGET_EXPR representing the result of __gnu_cxx::__normal_iterator<const int*, std::vector<int> >::operator++ But 'r' above refers to one of the int elements of the vector 'v', not to a temporary object. Therefore the warning is a false positive. I suppose code like the above is relatively common (the warning broke cppunit-1.15.1 and a few other projects), so presumably it makes sense to suppress the warning when it comes to member operator*. In this case it's defined as reference operator*() const _GLIBCXX_NOEXCEPT { return *_M_current; } and I'm guessing a lot of member operator* are like that, at least when it comes to iterators. I've looked at _Fwd_list_iterator, _Fwd_list_const_iterator, __shared_ptr_access, _Deque_iterator, istream_iterator, etc, and they're all like that, so adding #pragmas would be quite tedious. :/ PR c++/107488 gcc/cp/ChangeLog: * call.cc (do_warn_dangling_reference): Quash -Wdangling-reference for member operator*. gcc/testsuite/ChangeLog: * g++.dg/warn/Wdangling-reference5.C: New test.
