> I very much doubt it, when someone decides to make full of use of recent ISO C on a C library header file. I have tested this WRT _Generic as it was a concer

> I very much doubt it, when someone decides to make full of use of recent ISO C on a C library header file. I have tested this WRT _Generic as it was a concern. It turns out that GCC will accept it on older versions, which permits compatibility. You might feel that this is wrong, but that is how things are right now.