1isnan(3M) Mathematical Library Functions isnan(3M)
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6 isnan - test for NaN
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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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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
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31 Both the isnan() function and macro return non-zero if and only if x is
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35 No errors are defined.
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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45 is obsolete and will no longer work.
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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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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)