1ISUNORDERED(P)             POSIX Programmer's Manual            ISUNORDERED(P)
2
3
4

NAME

6       isunordered - test if arguments are unordered
7

SYNOPSIS

9       #include <math.h>
10
11       int isunordered(real-floating x, real-floating y);
12
13

DESCRIPTION

15       The  isunordered()  macro  shall  determine  whether  its arguments are
16       unordered.
17

RETURN VALUE

19       Upon successful completion, the isunordered() macro shall return  1  if
20       its arguments are unordered, and 0 otherwise.
21
22       If x or y is NaN, 0 shall be returned.
23

ERRORS

25       No errors are defined.
26
27       The following sections are informative.
28

EXAMPLES

30       None.
31

APPLICATION USAGE

33       The  relational  and  equality operators support the usual mathematical
34       relationships between numeric values. For any ordered pair  of  numeric
35       values,  exactly one of the relationships (less, greater, and equal) is
36       true. Relational operators may raise the invalid floating-point  excep‐
37       tion  when  argument values are NaNs. For a NaN and a numeric value, or
38       for two NaNs, just the unordered relationship is true. This macro is  a
39       quiet  (non-floating-point  exception  raising) version of a relational
40       operator. It facilitates writing efficient code that accounts for  NaNs
41       without suffering the invalid floating-point exception. In the SYNOPSIS
42       section, real-floating indicates that the argument shall be an  expres‐
43       sion of real-floating type.
44

RATIONALE

46       None.
47

FUTURE DIRECTIONS

49       None.
50

SEE ALSO

52       isgreater()  ,  isgreaterequal()  ,  isless() , islessequal() , isless‐
53       greater()  ,  the  Base  Definitions  volume  of  IEEE Std 1003.1-2001,
54       <math.h>
55

57       Portions  of  this text are reprinted and reproduced in electronic form
58       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
59       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
60       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
61       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
62       event of any discrepancy between this version and the original IEEE and
63       The  Open Group Standard, the original IEEE and The Open Group Standard
64       is the referee document. The original Standard can be  obtained  online
65       at http://www.opengroup.org/unix/online.html .
66
67
68
69IEEE/The Open Group                  2003                       ISUNORDERED(P)
Impressum