Originální popis anglicky:
isunordered - test if arguments are unordered
Návod, kniha: POSIX Programmer's Manual
#include <math.h>
int isunordered(real-floating
x, real-floating
y);
The
isunordered() macro shall determine whether its arguments are
unordered.
Upon successful completion, the
isunordered() macro shall return 1 if its
arguments are unordered, and 0 otherwise.
If
x or
y is NaN, 0 shall be returned.
No errors are defined.
The following sections are informative.
None.
The relational and equality operators support the usual mathematical
relationships between numeric values. For any ordered pair of numeric values,
exactly one of the relationships (less, greater, and equal) is true.
Relational operators may raise the invalid floating-point exception when
argument values are NaNs. For a NaN and a numeric value, or for two NaNs, just
the unordered relationship is true. This macro is a quiet (non-floating-point
exception raising) version of a relational operator. It facilitates writing
efficient code that accounts for NaNs without suffering the invalid
floating-point exception. In the SYNOPSIS section,
real-floating
indicates that the argument shall be an expression of
real-floating
type.
None.
None.
isgreater() ,
isgreaterequal() ,
isless() ,
islessequal() ,
islessgreater() , 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
.
