https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80943
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=86521 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- GCC 8.1.0-8.3.0 selected the one which printed 1 for C++17. GCC 8.4.0 and GCC 9+ all select the one which prints 2 for C++17. GCC 7.x all print 2. clang also prints 2 for C++17 and 1 for C++14. ICC prints 1 for both C++14 and C++17. See related to PR 86521 . Maybe someone with better understanding of the differences between C++14 and C++17 than I can help here. It is definitely related to C++17 mandatory of copy elision.