https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117981
--- Comment #1 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- Actually this might not be the goal of this option. It is documented as Warn about features not present in ISO C11, but present in ISO C23. Here, the issue is due to a feature not present in ISO C11, but present in ISO C23: due to the new feature in C23, the valid code in C11 will fail to compile in C23 mode (e.g. with newer GCC versions). But I suspect that this option *only* means to warn about C23-only features implemented in C11 mode. This should be clarified. In any case, there should be an option to warn about code that will become invalid in new standard modes (and even in new GNU modes) due to new features like new keywords (such as bool, false and true). And IMHO, this should be a generic option, i.e. which should also apply to future standards without having to change the option name.
