expands to a float constant representing positive infinity.
expands to a float constant representing a quiet NaN
NaN is a NaN ("not-a-number") that does not raise exceptions
when it is used in arithmetic.
The opposite is a
See IEC 60559:1989.
expand to constants of types double, float
and long double, respectively,
that represent a large positive value, possibly plus infinity.
On a glibc system, the macro
is always available.
Availability of the
macro can be tested using
and similarly for
They will be defined by
is defined, or
and has a value not less than 199901L.