ROUND(3) BSD Library Functions Manual ROUND(3)NAME
round, lround, llround — round to integral value, regardless of rounding
direction
SYNOPSIS
#include <math.h>
double
round(double x);
float
roundf(float x);
long int
lround(double x);
long int
lroundf(float x);
long long int
llround(double x);
long long int
llroundf(float x);
DESCRIPTION
The round() and roundf() functions return the integral value nearest to x
rounding half-way cases away from zero, regardless of the current round‐
ing direction.
The lround() , lroundf() , llround() and llroundf() 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 spec‐
ified. 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" float‐
ing-point exception for non-integer arguments that round to within the
range of the return type.
SEE ALSOabs(3), fabs(3), ceil(3), floor(3), ieee(3), math(3), rint(3)STANDARDS
The round() , roundf() , lround() , lroundf() , llround() , and
llroundf() functions conform to ISO/IEC 9899:1999(E).
BSD July 22, 2003 BSD