lround, lroundf, lroundl, llround, llroundf, llroundl - round to nearest integer
#include <math.h>
long int lround(double x);
long int lroundf(float x);
long int lroundl(long double x);
long long int llround(double x);
long long int llroundf(float x);
long long int llroundl(long double x);
Link with -lm
.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
All functions shown above:
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
These functions return the rounded integer value.
If x
is a NaN or an infinity, or the rounded value is too large to be stored in a long
(long long
in the case of the ll* functions), then a domain error occurs, and the return value is unspecified.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
x
is a NaN or infinite, or the rounded value is too largeAn invalid floating-point exception (FE_INVALID) is raised.
These functions do not set errno
.
These functions first appeared in glibc in version 2.1.
C99, POSIX.1-2001, POSIX.1-2008.
This page is part of release 4.15 of the Linux man-pages
project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.