NAME
nan, nanf,
nanl —
return quiet NaN
LIBRARY
library “libm”
SYNOPSIS
#include
<math.h>
double
nan(const
char *tagp);
float
nanf(const
char *tagp);
long double
nanl(const
char *tagp);
DESCRIPTION
The callnan("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
STANDARDS
The nan(), nanf(),
and nanl() functions conform to
ISO/IEC 9899:1999
(“ISO C99”).