функции округления точек (point rounding functions)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
nearbyint, nearbyintf, nearbyintl — floating-point rounding
functions
Синопсис (Synopsis)
#include <math.h>
double nearbyint(double x);
float nearbyintf(float x);
long double nearbyintl(long double x);
Описание (Description)
The functionality described on this reference page is aligned
with the ISO C standard. Any conflict between the requirements
described here and the ISO C standard is unintentional. This
volume of POSIX.1‐2017 defers to the ISO C standard.
These functions shall round their argument to an integer value in
floating-point format, using the current rounding direction and
without raising the inexact floating-point exception.
Возвращаемое значение (Return value)
Upon successful completion, these functions shall return the
rounded integer value. The result shall have the same sign as x.
If x is NaN, a NaN shall be returned.
If x is ±0, ±0 shall be returned.
If x is ±Inf, x shall be returned.
Ошибки (Error)
No errors are defined.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
The integral value returned by these functions need not be
expressible as an intmax_t. The return value should be tested
before assigning it to an integer type to avoid the undefined
results of an integer overflow.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
feclearexcept(3p), fetestexcept(3p)
The Base Definitions volume of POSIX.1‐2017, Section 4.20,
Treatment of Error Conditions for Mathematical Functions,
math.h(0p)
