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ROUND(3)			    Linux Programmer's Manual				 ROUND(3)

       round, roundf, roundl - round to nearest integer, away from zero

       #include <math.h>

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

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       round(), roundf(), roundl(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

       These  functions  round	x  to the nearest integer, but round halfway cases away from zero
       (regardless of the current rounding direction, see fenv(3)), instead  of  to  the  nearest
       even integer like rint(3).

       For example, round(0.5) is 1.0, and round(-0.5) is -1.0.

       These functions return the rounded integer value.

       If x is integral, +0, -0, NaN,  or infinite, x itself is returned.

       No errors occur.  POSIX.1-2001 documents a range error for overflows, but see NOTES.

       These functions first appeared in glibc in version 2.1.

       C99, POSIX.1-2001.

       POSIX.1-2001  contains  text  about overflow (which might set errno to ERANGE, or raise an
       FE_OVERFLOW exception).	In practice, the result cannot overflow on any	current  machine,
       so  this error-handling stuff is just nonsense.	(More precisely, overflow can happen only
       when the maximum value of the exponent is smaller than the number of mantissa  bits.   For
       the  IEEE-754  standard	32-bit and 64-bit floating-point numbers the maximum value of the
       exponent is 128 (respectively, 1024), and the number of mantissa bits is 24 (respectively,

       If you want to store the rounded value in an integer type, you probably want to use one of
       the functions described in lround(3) instead.

       ceil(3), floor(3), lround(3), nearbyint(3), rint(3), trunc(3)

       This page is part of release 3.25 of the Linux man-pages project.  A  description  of  the
       project,   and	information  about  reporting  bugs,  can  be  found  at  http://www.ker-

					    2008-08-11					 ROUND(3)
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