rint, rintf, rintl
The latest version of this topic can be found at rint, rintf, rintl.
Rounds a floating-point value to the nearest integer in floating-point format.
double rint( double x ); float rint( float x ); // C++ only long double rint( long double x ); // C++ only float rintf( float x ); long double rintl( long double x );
Parameters
x
The floating-point value to round.
The rint functions return a floating-point value that represents the nearest integer to x. Halfway values are rounded according to the current setting of the floating-point rounding mode, the same as the nearbyint functions. Unlike the nearbyint functions, the rint functions may raise the FE_INEXACT floating-point exception if the result differs in value from the argument. There is no error return.
| Input | SEH Exception | _matherr Exception |
|---|---|---|
| ± ∞, QNAN, IND | none | none |
| Denormals | EXCEPTION_FLT_UNDERFLOW | none |
Because C++ allows overloading, you can call overloads of rint that take and return float and long double values. In a C program, rint always takes and returns a double.
| Function | C header | C++ header |
|---|---|---|
rint, rintf, rintl | <math.h> | <cmath> |
For additional compatibility information, see Compatibility.
// crt_rint.c
// Build with: cl /W3 /Tc crt_rint.c
// This example displays the rounded results of
// the floating-point values 2.499999, -2.499999,
// 2.8, -2.8, 2.5 and -2.5.
#include <math.h>
#include <stdio.h>
int main( void )
{
double x = 2.499999;
float y = 2.8f;
long double z = 2.5;
printf("rint(%f) is %.0f\n", x, rint (x));
printf("rint(%f) is %.0f\n", -x, rint (-x));
printf("rintf(%f) is %.0f\n", y, rintf(y));
printf("rintf(%f) is %.0f\n", -y, rintf(-y));
printf("rintl(%Lf) is %.0Lf\n", z, rintl(z));
printf("rintl(%Lf) is %.0Lf\n", -z, rintl(-z));
}
rint(2.499999) is 2 rint(-2.499999) is -2 rintf(2.800000) is 3 rintf(-2.800000) is -3 rintl(2.500000) is 3 rintl(-2.500000) is -3
Floating-Point Support
ceil, ceilf, ceill
floor, floorf, floorl
fmod, fmodf
lrint, lrintf, lrintl, llrint, llrintf, llrintl
lround, lroundf, lroundl, llround, llroundf, llroundl
nearbyint, nearbyintf, nearbyintl
rint