https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86301
--- Comment #2 from zhonghao at pku dot org.cn --- (In reply to Jonathan Wakely from comment #1) > (In reply to zhonghao from comment #0) > > A previous version of clang++ produces similar error message for this code, > > but was fixed. > > No it didn't, the error shown in the Clang bug comes from GCC! > > Please make more effort to understand what you are doing, OR I WILL BAN YOUR > ACCOUNT. Did you try the latest g++ and clang++. They produce different results when they compile the code. My clang is 7.0.0. It does not produce any error messages for this code. Do the difference indicate bugs in g++?