lround (3)
Leading comments
Copyright 2001 Andries Brouwer <aeb@cwi.nl>.
and Copyright 2008, Linux Foundation, written by Michael Kerrisk
<mtk.manpages@gmail.com>
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NAME
lround, lroundf, lroundl, llround, llroundf, llroundl - round to nearest integer, away from zeroSYNOPSIS
#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:
-
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION
These functions round their argument to the nearest integer value, rounding away from zero, regardless of the current rounding direction (see fenv(3)).Note that unlike the round(3) and ceil(3), functions, the return type of these functions differs from that of their arguments.
RETURN VALUE
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.
ERRORS
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.The following errors can occur:
- Domain error: x is a NaN or infinite, or the rounded value is too large
- An invalid floating-point exception (FE_INVALID) is raised.
These functions do not set errno.
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 |
|
lround(),
lroundf(),
lroundl(),
llround(), llroundf(), llroundl() | Thread safety | MT-Safe |