ISINF(3) BSD Programmer's Manual ISINF(3)NAMEisinf - test for infinity
LIBRARY
libc
SYNOPSIS
#include <math.h>
int
isinf(real-floating x);
DESCRIPTION
The isinf() macro determines whether its argument x is an infinity (posi-
tive or negative). An argument represented in a format wider than its se-
mantic 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 infin-
ity. Otherwise 0 is returned.
SEE ALSOfpclassify(3), isfinite(3), isinff(3), isnan(3), isnanf(3), isnormal(3),
math(3), signbit(3)
IEEE Standard for Binary Floating-Point Arithmetic, Std 754-1985, ANSI.
STANDARDS
The isinf() macro conforms to ISO/IEC 9899:1999 ("ISO C99").
MirOS BSD #10-current March 5, 2004 1