NAN(3) | Library Functions Manual | NAN(3)

# NAME

nan, nanf, nanl — return quiet NaN

# LIBRARY

Math Library (libm, -lm)

# SYNOPSIS

#include <math.h>
double
nan(const char *tagp);
float
nanf(const char *tagp);
long double
nanl(const char *tagp);

# DESCRIPTION

The call nan("n-char-sequence") is equivalent to the call strtod("NAN(n-char-sequence)", NULL). The call nan("") is equivalent to the call strtod("NAN()", NULL).
The nanf() and nanl() functions are equivalent to nan() but substituting strtof() and strtold(), respectively.

# RETURN VALUES

## IEEE 754

The nan(), nanf(), and nanl() functions return a quiet NaN as specified by tagp.

## VAX

The nan(), nanf(), and nanl() functions return zero.

# SEE ALSO

math(3), strtod(3)

# STANDARDS

The nan(), nanf(), and nanl() functions conform to ISO/IEC 9899:1999 (“ISO C99”).

March 15, 2006 | NetBSD 8.2