1NEARBYINT(3P)              POSIX Programmer's Manual             NEARBYINT(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       nearbyint, nearbyintf, nearbyintl — floating-point rounding functions
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SYNOPSIS

15       #include <math.h>
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17       double nearbyint(double x);
18       float nearbyintf(float x);
19       long double nearbyintl(long double x);
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DESCRIPTION

22       The functionality described on this reference page is aligned with  the
23       ISO C  standard.  Any  conflict between the requirements described here
24       and the ISO C standard is unintentional. This  volume  of  POSIX.1‐2017
25       defers to the ISO C standard.
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27       These  functions  shall  round  their  argument  to an integer value in
28       floating-point format, using the current rounding direction and without
29       raising the inexact floating-point exception.
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RETURN VALUE

32       Upon  successful  completion,  these functions shall return the rounded
33       integer value.  The result shall have the same sign as x.
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35       If x is NaN, a NaN shall be returned.
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37       If x is ±0, ±0 shall be returned.
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39       If x is ±Inf, x shall be returned.
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ERRORS

42       No errors are defined.
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44       The following sections are informative.
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EXAMPLES

47       None.
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APPLICATION USAGE

50       The integral value returned by these functions need not be  expressible
51       as  an intmax_t.  The return value should be tested before assigning it
52       to an integer type to avoid the undefined results of an  integer  over‐
53       flow.
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RATIONALE

56       None.
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FUTURE DIRECTIONS

59       None.
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SEE ALSO

62       feclearexcept(), fetestexcept()
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64       The Base Definitions volume of POSIX.1‐2017, Section 4.20, Treatment of
65       Error Conditions for Mathematical Functions, <math.h>
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68       Portions of this text are reprinted and reproduced in  electronic  form
69       from  IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
70       table Operating System Interface (POSIX), The Open Group Base  Specifi‐
71       cations  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of
72       Electrical and Electronics Engineers, Inc and The Open Group.   In  the
73       event of any discrepancy between this version and the original IEEE and
74       The Open Group Standard, the original IEEE and The Open Group  Standard
75       is  the  referee document. The original Standard can be obtained online
76       at http://www.opengroup.org/unix/online.html .
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78       Any typographical or formatting errors that appear  in  this  page  are
79       most likely to have been introduced during the conversion of the source
80       files to man page format. To report such errors,  see  https://www.ker‐
81       nel.org/doc/man-pages/reporting_bugs.html .
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85IEEE/The Open Group                  2017                        NEARBYINT(3P)
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