isinf(3) - NetBSD Manual Pages

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ISINF(3)                NetBSD Library Functions Manual               ISINF(3)


NAME

     isinf -- test for infinity


LIBRARY

     Standard C Library (libc, -lc)


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
     semantic type is converted to its semantic type first.  The determination
     is then based on the type of the argument.


RETURN VALUES

     The isinf() macro returns a non-zero value if the value of x is an infin-
     ity.  Otherwise 0 is returned.


SEE ALSO

     fpclassify(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'').


CAVEATS

     On VAX the isinf() function always returns 0, as the architecture doesn't
     have a representation for infinity.

NetBSD 10.0                   September 27, 2017                   NetBSD 10.0