NAME
isinf
- test for infinity
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
int
isinf(
real-floating x
)
DESCRIPTION
The
isinf(
)
macro determines whether its argument
x
is an infinity (positive or negative).
An argument represented in a format wider than its semantic type is
converted to its semantic type first.
The determination is then based on the type of the argument.
IEEE 754
It is determined whether the value of
x
is an infinity.
VAX
Infinities are not supported.
RETURN VALUES
The
isinf(
)
macro returns a non-zero value if the value of
x
is an infinity.
Otherwise 0 is returned.
SEE ALSO
fpclassify(3),
isfinite(3),
isinff(3),
isnan(3),
isnanf(3),
isnormal(3),
math(3),
signbit(3)
STANDARDS
The
isinf(
)
macro conforms to
ISO/IEC 9899:1999 (``ISO C99'') .