1ISLESS(P)                  POSIX Programmer's Manual                 ISLESS(P)
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NAME

6       isless - test if x is less than y
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SYNOPSIS

9       #include <math.h>
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11       int isless(real-floating x, real-floating y);
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DESCRIPTION

15       The  isless()  macro shall determine whether its first argument is less
16       than its second argument. The value of isless( x, y) shall be equal  to
17       (x) < (y); however, unlike (x) < (y), isless( x, y) shall not raise the
18       invalid floating-point exception when x and y are unordered.
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RETURN VALUE

21       Upon successful completion, the isless() macro shall return  the  value
22       of (x) < (y).
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24       If x or y is NaN, 0 shall be returned.
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ERRORS

27       No errors are defined.
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29       The following sections are informative.
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EXAMPLES

32       None.
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APPLICATION USAGE

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

48       None.
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FUTURE DIRECTIONS

51       None.
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SEE ALSO

54       isgreater()  ,  isgreaterequal()  ,  islessequal()  , islessgreater() ,
55       isunordered() , the Base Definitions  volume  of  IEEE Std 1003.1-2001,
56       <math.h>
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59       Portions  of  this text are reprinted and reproduced in electronic form
60       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
61       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
62       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
63       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
64       event of any discrepancy between this version and the original IEEE and
65       The  Open Group Standard, the original IEEE and The Open Group Standard
66       is the referee document. The original Standard can be  obtained  online
67       at http://www.opengroup.org/unix/online.html .
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71IEEE/The Open Group                  2003                            ISLESS(P)
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