1ISLESSEQUAL(3P)            POSIX Programmer's Manual           ISLESSEQUAL(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       islessequal — test if x is less than or equal to y
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SYNOPSIS

15       #include <math.h>
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17       int islessequal(real-floating x, real-floating y);
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DESCRIPTION

20       The functionality described on this reference page is aligned with  the
21       ISO C  standard.  Any  conflict between the requirements described here
22       and the ISO C standard is unintentional. This  volume  of  POSIX.1‐2017
23       defers to the ISO C standard.
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25       The  islessequal()  macro shall determine whether its first argument is
26       less than or equal to its second argument. The value of  islessequal(x,
27       y)  shall  be equal to (x) <= (y); however, unlike (x) <= (y), islesse‐
28       qual(x, y) shall not raise the invalid floating-point exception when  x
29       and y are unordered.
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RETURN VALUE

32       Upon  successful  completion,  the islessequal() macro shall return the
33       value of (x) <= (y).
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35       If x or y is NaN, 0 shall be returned.
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ERRORS

38       No errors are defined.
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40       The following sections are informative.
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EXAMPLES

43       None.
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APPLICATION USAGE

46       The relational and equality operators support  the  usual  mathematical
47       relationships  between  numeric values. For any ordered pair of numeric
48       values, exactly one of the relationships (less, greater, and equal)  is
49       true.  Relational operators may raise the invalid floating-point excep‐
50       tion when argument values are NaNs. For a NaN and a numeric  value,  or
51       for  two NaNs, just the unordered relationship is true. This macro is a
52       quiet (non-floating-point exception raising) version  of  a  relational
53       operator.  It facilitates writing efficient code that accounts for NaNs
54       without suffering the invalid floating-point exception. In the SYNOPSIS
55       section,  real-floating indicates that the argument shall be an expres‐
56       sion of real-floating type.
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RATIONALE

59       None.
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FUTURE DIRECTIONS

62       None.
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SEE ALSO

65       isgreater(), isgreaterequal(), isless(), islessgreater(), isunordered()
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67       The Base Definitions volume of POSIX.1‐2017, <math.h>
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70       Portions of this text are reprinted and reproduced in  electronic  form
71       from  IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
72       table Operating System Interface (POSIX), The Open Group Base  Specifi‐
73       cations  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of
74       Electrical and Electronics Engineers, Inc and The Open Group.   In  the
75       event of any discrepancy between this version and the original IEEE and
76       The Open Group Standard, the original IEEE and The Open Group  Standard
77       is  the  referee document. The original Standard can be obtained online
78       at http://www.opengroup.org/unix/online.html .
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80       Any typographical or formatting errors that appear  in  this  page  are
81       most likely to have been introduced during the conversion of the source
82       files to man page format. To report such errors,  see  https://www.ker‐
83       nel.org/doc/man-pages/reporting_bugs.html .
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87IEEE/The Open Group                  2017                      ISLESSEQUAL(3P)
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