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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
strod(
"NAN(n-char-sequence)",
NULL). The call
nan(
"") is equivalent to the call
strod(
"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.
STANDARDS
The nan(), nanf(), and nanl() functions conform to ISO/IEC 9899:1999 (“ISO C99”).