trunc, truncf, truncl - round to integer, toward zero
Math library (libm
, -lm
)
#include <math.h>
double trunc(double x);
float truncf(float x);
long double truncl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions round x
to the nearest integer value that is
not larger in magnitude than x
.
These functions return the rounded integer value, in floating format.
If x
is integral, infinite, or NaN, x
itself is
returned.
No errors occur.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
Thread safety | MT-Safe |
C11, POSIX.1-2008.
glibc 2.1. C99, POSIX.1-2001.
The integral value returned by these functions may be too large to
store in an integer type (int
, long
, etc.). To avoid
an overflow, which will produce undefined results, an application should
perform a range check on the returned value before assigning it to an
integer type.