Section (3) nan
Name
nan, nanf, nanl — return _zsingle_quotesz_Not a Number_zsingle_quotesz_
Synopsis
#include <math.h>
double
nan( |
const char *tagp) ; |
float
nanf( |
const char *tagp) ; |
long double
nanl( |
const char *tagp) ; |
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DESCRIPTION
These functions return a representation (determined by
tagp
) of a quiet NaN.
If the implementation does not support quiet NaNs, these
functions return zero.
The call nan(char-sequence)
is
equivalent to:
strtod(NAN(char-sequence), NULL);
Similarly, calls to nanf
()
and nanl
() are equivalent to
analogous calls to strtof(3) and strtold(3).
The argument tagp
is used in an unspecified manner. On IEEE 754 systems, there
are many representations of NaN, and tagp
selects one. On other
systems it may do nothing.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
nan (), nanf (), nanl () |
Thread safety | MT-Safe locale |
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008. See also IEC 559 and the appendix with recommended functions in IEEE 754/IEEE 854.
COLOPHON
This page is part of release 4.16 of the Linux man-pages
project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
Copyright 2002 Walter Harms (walter.harmsinformatik.uni-oldenburg.de) %%%LICENSE_START(GPL_NOVERSION_ONELINE) Distributed under GPL %%%LICENSE_END Based on glibc infopages Corrections by aeb |