NAME
nan —
generate a quiet NaN
SYNOPSIS
#include
<math.h>
double
nan(const
char *tagp);
long double
nanl(const
char *tagp);
float
nanf(const
char *tagp);
DESCRIPTION
The
nan()
functions return a quiet NaN, whose trailing fraction field contains the
result of converting tagp to an unsigned integer. If
tagp is too large to be contained in the trailing
fraction field of the NaN, then the least significant bits of the integer
represented by tagp are used.
SPECIAL VALUES
If tagp contains any non-numeric characters, the function returns a NaN whos trailing fraction field is zero.
If tagp is empty, the function returns a NaN whos trailing fraction field is zero.
STANDARDS
The nan() functions conform to ISO/IEC
9899:2011.