It's similar in C. C11 Standard chapter 7.1.3: >All identifiers that begin with an underscore and either an uppercase letter or another underscore are always r

It's similar in C. C11 Standard chapter 7.1.3: >All identifiers that begin with an underscore and either an uppercase letter or another underscore are always reserved for any use. I doubt the library is usable in C++ though, since longjmp doesn't play well with the destruction of local objects.