**roundf**

#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 ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION
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.
RETURN VALUE
These functions return the rounded integer value.
If x is integral, +0, -0, NaN, or infinite, x itself is returned.
ERRORS
No errors occur. POSIX.1-2001 documents a range error for overflows,
but see NOTES.
VERSIONS
These functions first appeared in glibc in version 2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see
**attributes(7)**.
+----------------------------+---------------+---------+
|Interface | Attribute | Value |
+----------------------------+---------------+---------+
|round(), roundf(), roundl() | Thread safety | MT-Safe |
+----------------------------+---------------+---------+
CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
NOTES
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 max-
imum 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 num-
http://www.kernel.org/doc/man-pages/.
2015-04-19 **ROUND(3)**

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