#include <iostream>
#include <cmath>
#include <cfenv>
using namespace std;
int main()
{
fesetround(FE_TONEAREST);
cout << "rounding to nearest :" << endl;
cout << "nearbyint(3.3) = " << nearbyint(3.3) << endl;
cout << "nearbyint(3.5) = " << nearbyint(3.5) << endl;
cout << "nearbyint(4.5) = " << nearbyint(4.5) << endl;
cout << "nearbyint(4.6) = " << nearbyint(4.6) << endl;
cout << "nearbyint(-3.3) = " << nearbyint(-3.3) << endl;
cout << "nearbyint(-3.5) = " << nearbyint(-3.5) << endl;
cout << "nearbyint(-4.5) = " << nearbyint(-4.5) << endl;
cout << "nearbyint(-4.6) = " << nearbyint(-4.6) << endl << endl;
fesetround(FE_DOWNWARD);
cout << "rounding down: " << endl;
cout << "nearbyint(3.3) = " << nearbyint(3.3) << endl;
cout << "nearbyint(3.5) = " << nearbyint(3.5) << endl;
cout << "nearbyint(4.5) = " << nearbyint(4.5) << endl;
cout << "nearbyint(4.6) = " << nearbyint(4.6) << endl;
cout << "nearbyint(-3.3) = " << nearbyint(-3.3) << endl;
cout << "nearbyint(-3.5) = " << nearbyint(-3.5) << endl;
cout << "nearbyint(-4.5) = " << nearbyint(-4.5) << endl;
cout << "nearbyint(-4.6) = " << nearbyint(-4.6) << endl << endl;;
fesetround(FE_UPWARD);
cout << "rounding up: " << endl;
cout << "nearbyint(3.3) = " << nearbyint(3.3) << endl;
cout << "nearbyint(3.5) = " << nearbyint(3.5) << endl;
cout << "nearbyint(4.5) = " << nearbyint(4.5) << endl;
cout << "nearbyint(4.6) = " << nearbyint(4.6) << endl;
cout << "nearbyint(-3.3) = " << nearbyint(-3.3) << endl;
cout << "nearbyint(-3.5) = " << nearbyint(-3.5) << endl;
cout << "nearbyint(-4.5) = " << nearbyint(-4.5) << endl;
cout << "nearbyint(-4.6) = " << nearbyint(-4.6) << endl << endl;
fesetround(FE_TOWARDZERO);
cout << "rounding toward zero: " << endl;
cout << "nearbyint(3.3) = " << nearbyint(3.3) << endl;
cout << "nearbyint(3.5) = " << nearbyint(3.5) << endl;
cout << "nearbyint(4.5) = " << nearbyint(4.5) << endl;
cout << "nearbyint(4.6) = " << nearbyint(4.6) << endl;
cout << "nearbyint(-3.3) = " << nearbyint(-3.3) << endl;
cout << "nearbyint(-3.5) = " << nearbyint(-3.5) << endl;
cout << "nearbyint(-4.5) = " << nearbyint(-4.5) << endl;
cout << "nearbyint(-4.6) = " << nearbyint(-4.6) << endl;
return 0;
}
/*
run:
rounding to nearest :
nearbyint(3.3) = 3
nearbyint(3.5) = 4
nearbyint(4.5) = 4
nearbyint(4.6) = 5
nearbyint(-3.3) = -3
nearbyint(-3.5) = -4
nearbyint(-4.5) = -4
nearbyint(-4.6) = -5
rounding down:
nearbyint(3.3) = 3
nearbyint(3.5) = 3
nearbyint(4.5) = 4
nearbyint(4.6) = 4
nearbyint(-3.3) = -4
nearbyint(-3.5) = -4
nearbyint(-4.5) = -5
nearbyint(-4.6) = -5
rounding up:
nearbyint(3.3) = 4
nearbyint(3.5) = 4
nearbyint(4.5) = 5
nearbyint(4.6) = 5
nearbyint(-3.3) = -3
nearbyint(-3.5) = -3
nearbyint(-4.5) = -4
nearbyint(-4.6) = -4
rounding toward zero:
nearbyint(3.3) = 3
nearbyint(3.5) = 3
nearbyint(4.5) = 4
nearbyint(4.6) = 4
nearbyint(-3.3) = -3
nearbyint(-3.5) = -3
nearbyint(-4.5) = -4
nearbyint(-4.6) = -4
*/
