QNAN 3CW "09 March 2006" "mathcw-1.00"

Table of contents


NAME

qnanf, qnan, qnanl, qnanw, qnanq, qnanll, qnandf, qnand, qnandl, qnandll - quiet NaN function

SYNOPSIS

cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ]

#include <mathcw.h>

extern float qnanf (const char *tag);

extern double qnan (const char *tag);

extern long double qnanl (const char *tag);

extern __float80 qnanw (const char *tag);

extern __float128 qnanq (const char *tag);

extern long_long_double qnanll (const char *tag);

extern decimal_float qnandf (const char *tag);

extern decimal_double qnand (const char *tag);

extern decimal_long_double qnandl (const char *tag);

extern decimal_long_long_double qnandll (const char *tag);

NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.


DESCRIPTION

Compute a quiet NaN, setting its content according to the string pointed to by the argument.

In the mathcw library, the argument is expected to be string containing an unsigned hexadecimal integer, with an optional 0x prefix. Its low-order bits are installed in the low-order significand bits.

If the argument string is empty, or is a NULL pointer, an internal counter is incremented on each call and installed in the low-order significand bits.


RETURN VALUES

Return a freshly-computed quiet NaN, or zero if NaNs are not supported.

ERRORS

In IEEE 754 and 854 arithmetic, the invalid exception flag is always set, but errno is never set.

SEE ALSO

isnan(3CW), isqnan(3CW), issnan(3CW), nan(3CW), snan(3CW).