Can an implementation ``pre-qualify'' a standard type?

[Doug Gwyn]

In article <1991Jun10.232144.24618 at twinsun.com> eggert at twinsun.com (Paul Eggert) writes:
>	typedef volatile int sig_atomic_t;
>...  Rumor has it that at least one would-be
>conforming implementation does this to head off common programming errors.

That would not be a conforming implementation:
	(1) sig_atomic_t is required to be an "integral type", which is a
	technical term defined only as an unqualified type.
	(2) "volatile sig_atomic_t" is explicitly required to be supported,
	and if the typedef includes volatile qualification then the usage
	would violate a constraint in section 3.5.3 (X3.159-1989).