This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       The  integral value returned by these functions need not be expressible as an intmax_t.  The return value
       should be tested before assigning it to an integer type to avoid the  undefined  results  of  an  integer
       overflow.

       These  functions  may  raise the inexact floating-point exception if the result differs in value from the
       argument.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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 .

       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.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                         ROUND(3POSIX)

       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.1‐2017 defers to the ISO C standard.

       These  functions  shall  round  their  argument  to  the  nearest integer value in floating-point format,
       rounding halfway cases away from zero, regardless of the current rounding direction.

       No errors are defined.

       Thefollowingsectionsareinformative.

       None.

       None.

       round, roundf, roundl — round to the nearest integer value in a floating-point format

       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.

       None.

       Upon successful completion, these functions shall return the rounded integer  value.   The  result  shall
       have the same sign as x.

       If x is NaN, a NaN shall be returned.

       If x is ±0 or ±Inf, x shall be returned.

feclearexcept(), fetestexcept()

       The Base Definitions volume of POSIX.1‐2017, Section4.20, TreatmentofErrorConditionsforMathematicalFunctions, <math.h>

       #include <math.h>

       double round(double x);
       float roundf(float x);
       long double roundl(long double x);