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round(3p) — Linux manual page

ROUND(3P)               POSIX Programmer's ManualROUND(3P)

PROLOG        top

       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        top

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

SYNOPSIS        top

       #include <math.h>       double round(doublex);       float roundf(floatx);       long double roundl(long doublex);

DESCRIPTION        top

       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.

RETURN VALUE        top

       Upon successful completion, these functions shall return the       rounded integer value.  The result shall have the same sign asx.       Ifx is NaN, a NaN shall be returned.       Ifx is ±0 or ±Inf,x shall be returned.

ERRORS        top

       No errors are defined.The following sections are informative.

EXAMPLES        top

       None.

APPLICATION USAGE        top

       The integral value returned by these functions need not be       expressible as anintmax_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.

RATIONALE        top

       None.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

feclearexcept(3p),fetestexcept(3p)       The Base Definitions volume of POSIX.1‐2017,Section 4.20,Treatment of Error Conditions for Mathematical Functions,math.h(0p)

COPYRIGHT        top

       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 athttp://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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017ROUND(3P)

Pages that refer to this page:math.h(0p), rint(3p)

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