rintf (3)
NAME
nearbyint, nearbyintf, nearbyintl, rint, rintf, rintl - round to nearest integerSYNOPSIS
#include <math.h>
double nearbyint(double x); float nearbyintf(float x); long double nearbyintl(long double x);
double rint(double x); float rintf(float x); long double rintl(long double x);Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
nearbyint(), nearbyintf(), nearbyintl():
_POSIX_C_SOURCE >= 200112L || _ISOC99_SOURCE
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| _XOPEN_SOURCE >= 500
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
|| _XOPEN_SOURCE >= 500
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
DESCRIPTION
The nearbyint(), nearbyintf(), and nearbyintl() functions round their argument to an integer value in floating-point format, using the current rounding direction (see fesetround(3)) and without raising the inexact exception. When the current rounding direction is to nearest, these functions round halfway cases to the even integer in accordance with IEEE-754. The rint(), rintf(), and rintl() functions do the same, but will raise the inexact exception (FE_INEXACT, checkable via fetestexcept(3)) when the result differs in value from the argument.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.ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).Interface | Attribute | Value |
nearbyint (), nearbyintf (), nearbyintl (), rint (), rintf (), rintl () | Thread safety | MT-Safe |