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Math Library (libm, -lm)

#include <math.h>

The
`fpclassify()`
macro takes an argument of
x
and returns one of the following manifest constants.

FP_INFINITE
| Indicates that x is an infinite number. |

FP_NAN
| Indicates that x is not a number (NaN). |

FP_NORMAL
| Indicates that x is a normalized number. |

FP_SUBNORMAL
| |

Indicates that x is a denormalized number. | |

FP_ZERO
| Indicates that x is zero (0 or -0). |

The
`isfinite()`
macro returns a non-zero value if and only if its argument has
a finite (zero, subnormal, or normal) value.
The
`isinf()`,
`isnan()`,
and
`isnormal()`
macros return non-zero if and only if
x
is an infinity, NaN,
or a non-zero normalized number, respectively.

The symbol
`isnanf()`
is provided as an alias to
`isnan()`
for compatibility, and its use is deprecated.
Similarly,
`finite()`
and
`finitef()`
are deprecated versions of
`isfinite()`.

The
`fpclassify()`,
`isfinite()`,
`isinf()`,
`isnan()`,
and
`isnormal()`
macros conform to
ISO/IEC 9899:1999 ("ISO C99").

The
`fpclassify()`,
`isfinite()`,
`isinf()`,
`isnan()`,
and
`isnormal()`
macros were added in
FreeBSD 5.1 .
*BSD 3*
introduced
`isinf()`
and
`isnan()`
functions, which accepted
double
arguments; these have been superseded by the macros
described above.

FPCLASSIFY (3) | January 26, 2005 |

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