https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122625
--- Comment #10 from d7d1cd <d7d1cd at mail dot ru> --- Thanks for the correction, but there's a caveat... If you add the -Wall -Werror -O0 compilation options to the original example, it links successfully (https://godbolt.org/z/4r59razqc). However, if you specify -O2 or -O3 optimization (https://godbolt.org/z/3fsxc1Tx1), you'll get a warning: include/c++/16.0.0/bits/stl_iterator.h:1111:16: error: array subscript 2 is outside array bounds of 'const char32_t [1]' [-Werror=array-bounds=] 1111 | { return __normal_iterator(_M_current++); } include/c++/16.0.0/format:847:28: note: at offset 8 into object '__arr' of size 4 847 | const char32_t __arr[1]{ __fill_char }; Compiler 15.2 doesn't have this problem.
