https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87504
--- Comment #3 from David Malcolm <dmalcolm at gcc dot gnu.org> --- After r267273, g++ emits: test.cc:10:30: error: invalid operands of types ‘const char [6]’ and ‘const char’ to binary ‘operator&’ 10 | return __builtin_strnlen (a&a[v0], n); | ~^~~~~~ | | | | | const char | const char [6] showing the types of the LHS and RHS (and using different colors for them). The message isn't changed yet, so keeping this open.