https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106175
--- Comment #2 from KL <deco33000 at yandex dot com> --- During the parsing stage, the compiler has this information. It knows that we want the end of v. So it can inject a comparison into the resulting code. A segfault here is not acceptable for a language like C++. There is no trap for the compiler here. That comparison is cheap.