huschi.net

ISLESS(3P)                 POSIX Programmer's Manual                ISLESS(3P)
PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       isless -- test if x is less than y
SYNOPSIS
       #include <math.h>
       int isless(real-floating x, real-floating y);
DESCRIPTION
       The functionality described on this reference page is aligned with  the
       ISO C  standard.  Any  conflict between the requirements described here
       and the ISO C standard is unintentional. This  volume  of  POSIX.1-2008
       defers to the ISO C standard.
       The  isless()  macro shall determine whether its first argument is less
       than its second argument. The value of isless(x, y) shall be  equal  to
       (x) < (y);  however, unlike (x) < (y), isless(x, y) shall not raise the
       invalid floating-point exception when x and y are unordered.
RETURN VALUE
       Upon successful completion, the isless() macro shall return  the  value
       of (x) < (y).
       If x or y is NaN, 0 shall be returned.
ERRORS
       No errors are defined.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       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  excep-
       tion  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  expres-
       sion of real-floating type.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       isgreater(),    isgreaterequal(),    islessequal(),    islessgreater(),
       isunordered()
       The Base Definitions volume of POSIX.1-2008, <math.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) 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.unix.org/online.html .
       Any  typographical  or  formatting  errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files  to  man page format. To report such errors, see https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                           ISLESS(3P)