https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83028
Bug ID: 83028 Summary: Incorrect -Wsequence-point warning in correct C++17 code with new evaluation order rules Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: ixsci at yandex dot ru Target Milestone: --- Compiling the following code: #include <iostream> using namespace std; int main() { int i = 0; cout << i++ << " " << i++ << "\n"; }; with the latest gcc (compiled on wandbox.org) and -std=c++1z gives the following warning: operation on 'i' may be undefined [-Wsequence-point] cout << i++ << " " << i++ << "\n"; But there should be no warnings since both modifications are sequenced and the result is well defined.