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man pages section 3: Extended Library Functions, Volume 2

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Updated: Thursday, June 13, 2019
 
 

nanl(3M)

Name

nan, nanf, nanl - return quiet NaN

Synopsis

c99 [ flag... ] file... –lm [ library... ]
#include <math.h>

double nan(const char *tagp);
float nanf(const char *tagp);
long double nanl(const char *tagp);

Description

The function call nan("n-char-sequence") is equivalent to:

strtod("NAN(n-char-sequence)", (char **) NULL);

The function call nan(" ") is equivalent to:

strtod("NAN()", (char **) NULL)

If tagp does not point to an n-char sequence or an empty string, the function call is equivalent to:

strtod("NAN", (char **) NULL)

Function calls to nanf() and nanl() are equivalent to the corresponding function calls to strtof() and strtold(). See strtod(3C).

Return Values

These functions return a quiet NaN.

Errors

No errors are defined.

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
Availability
system/library/math
MT-Level
MT-Safe
Standard

See Also

strtod(3C), math.h(3HEAD), attributes(7), standards(7)