1isnan(3M)               Mathematical Library Functions               isnan(3M)
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NAME

6       isnan - test for NaN
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SYNOPSIS

9       cc [ flag... ] file... -lm [ library... ]
10       #include <math.h>
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12       int isnan(double x);
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15       c99 [ flag... ] file... -lm [ library... ]
16       #include <math.h>
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18       int isnan(real—floating x);
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DESCRIPTION

22       In C90 mode, the isnan() function tests whether x is NaN.
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25       In C99 mode, the isnan() macro determines whether its argument value is
26       NaN. First, an argument represented in a format wider than its semantic
27       type is converted to its semantic type. The determination is then based
28       on the type of the argument.
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RETURN VALUES

31       Both the isnan() function and macro return non-zero if and only if x is
32       NaN.
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ERRORS

35       No errors are defined.
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WARNINGS

38       In  C99  mode,  the  practice  of  explicitly supplying a prototype for
39       isnan() after the line
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41         #include <math.h>
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45       is obsolete and will no longer work.
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ATTRIBUTES

48       See attributes(5) for descriptions of the following attributes:
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53       ┌─────────────────────────────┬─────────────────────────────┐
54       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
55       ├─────────────────────────────┼─────────────────────────────┤
56       │Interface Stability          │Standard                     │
57       ├─────────────────────────────┼─────────────────────────────┤
58       │MT-Level                     │MT-Safe                      │
59       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

62       fpclassify(3M), isfinite(3M), isinf(3M),  isnormal(3M),  math.h(3HEAD),
63       signbit(3M), attributes(5), standards(5)
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67SunOS 5.11                        12 Jul 2006                        isnan(3M)
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