ROUND(3)

NAME
round, lround, llround - round to integral value, regardless of rounding direction

SYNOPSIS
#include <math.h>
double
round(double x);
long double
roundl(long double x);
float
roundf(float x);
long int
lround(double x);
long int
lroundl(long double x);
long int
lroundf(float x);
long long int
llround(double x);
long long int
llroundl(long double x);
long long int
llroundf(float x);

DESCRIPTION
The round() functions return the integral value nearest to x rounding half-way cases away from zero, regardless of the current rounding direction.

The lround() and llround() functions return the integral value nearest to x (rounding half-way cases away from zero, regardless of the current rounding direction) in the return formats specified. If the rounded value is outside the range of the return type, the numeric result is unspecified and the "invalid" floating-point exception is raised. A range error may occur if the magnitude of x is too large.

SPECIAL VALUES
round(±0) returns ±0.

round(±infinity) returns ±infinity.

The round() functions may, but are not required to, raise the "inexact" floating-point exception for non-integer numeric arguments.

The lround() and llround() functions need not raise the "inexact" floating-point exception for non-integer arguments that round to within the range of the return type.

SEE ALSO
abs(3), fabs(3), ceil(3), floor(3), math(3), rint(3)

STANDARDS
The round() , lround() , and llround() functions conform to ISO/IEC 9899:1999(E).