long doubles at the moment (printf truncates them to doubles).
However, long doubles to appear to work to the ranges listed in this
commit on both -stable (4.5) and -current. There may be some slight
rounding issues with long doubles, but that's an orthogonal issue to
these constants.
I've had this in my local tree for 3 months, and in my company's local
tree for 15 months with no ill effects.
Obtained from: NetBSD
Not likely to like it: bde
59e43a0396