https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67200
TC <rs2740 at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #1 from TC <rs2740 at gmail dot com> --- Appears to be fixed in GCC 6, presumably by the delayed folding changes: main.cpp: In function 'A f()': main.cpp:9:23: error: use of deleted function 'A::A(const A&)' return true ? a : a; ^ main.cpp:3:5: note: declared here A(const A&) = delete; ^