C++ <cfenv> - fesetround() Function
The C++ <cfenv> fesetround() function attempts to set the current floating-point rounding direction mode as specified by rdir. Programs calling this function shall ensure that pragma FENV_ACCESS is enabled for the call.
Syntax
int fesetround (int rdir);
Parameters
rdir |
Specify rounding direction, one of floating-point rounding macros. All possible rounding direction modes are:
Certain library implementations may define additional floating-point rounding direction macro constants (with their corresponding macros also beginning with FE_). |
Return Value
Returns 0 if the requested rounding direction is successfully set, non-zero otherwise.
Exception
This function never throws exceptions.
Example:
The example below shows the usage of fesetround() function.
#include <iostream>
#include <cfenv>
#include <cmath>
#pragma STDC FENV_ACCESS ON
using namespace std;
int main (){
cout<<"Rounding 10.9\n";
//upward rounding direction mode
fesetround(FE_UPWARD);
cout<<"FE_UPWARD: "<<rint(10.9)<<"\n";
//downward rounding direction mode
fesetround(FE_DOWNWARD);
cout<<"FE_DOWNWARD: "<<rint(10.9)<<"\n";
//toward-zero rounding direction mode
fesetround(FE_TOWARDZERO);
cout<<"FE_TOWARDZERO: "<<rint(10.9)<<"\n";
//to-nearest rounding direction mode
fesetround(FE_TONEAREST);
cout<<"FE_TONEAREST: "<<rint(10.9)<<"\n";
return 0;
}
The output of the above code will be:
Rounding 10.9 FE_UPWARD: 11 FE_DOWNWARD: 10 FE_TOWARDZERO: 10 FE_TONEAREST: 11
❮ C++ <cfenv> Library
