округлить до ближайшего целого числа (round to nearest integer)
Имя (Name)
lround, lroundf, lroundl, llround, llroundf, llroundl - round to
nearest integer
Синопсис (Synopsis)
#include <math.h>
long lround(double x);
long lroundf(float x);
long lroundl(long double x);
long long llround(double x);
long long llroundf(float x);
long long 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
Описание (Description)
These functions round their argument to the nearest integer
value, rounding halfway cases 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.
Возвращаемое значение (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.
Ошибки (Error)
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.
Версии (Versions)
These functions first appeared in glibc in version 2.1.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────────────────┼───────────────┼─────────┤
│lround(), lroundf(), lroundl(), │ Thread safety │ MT-Safe │
│llround(), llroundf(), llroundl() │ │ │
└──────────────────────────────────────┴───────────────┴─────────┘
Стандарты (Conforming to)
C99, POSIX.1-2001, POSIX.1-2008.
Смотри также (See also)
ceil(3), floor(3), lrint(3), nearbyint(3), rint(3), round(3)
