Originální popis anglicky:
nan, nanf, nanl - return quiet NaN
Návod, kniha: POSIX Programmer's Manual
#include <math.h>
double nan(const char *
tagp);
float nanf(const char *
tagp);
long double nanl(const char *
tagp);
The function call
nan("
n-char-sequence") shall be
equivalent to:
strtod("NAN(n-char-sequence)", (char **) NULL);
The function call
nan("") shall be equivalent to:
strtod("NAN()", (char **) NULL)
If
tagp does not point to an
n-
char sequence or an empty
string, the function call shall be equivalent to:
strtod("NAN", (char **) NULL)
Function calls to
nanf() and
nanl() are equivalent to the
corresponding function calls to
strtof() and
strtold().
These functions shall return a quiet NaN, if available, with content indicated
through
tagp.
If the implementation does not support quiet NaNs, these functions shall return
zero.
No errors are defined.
The following sections are informative.
None.
None.
None.
None.
strtod() ,
strtold() , the Base Definitions volume of
IEEE Std 1003.1-2001,
<math.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
