Remainder
Defined in header <cmath>
.
Description
The IEEE floating-point remainder of the division operation x / y
calculated by this function is exactly the value x - quo * y
, where the value quo
is the integral value nearest the exact value x / y
. When |quo-x/y| = ½
, the value quo is chosen to be even.
In contrast to std::fmod, the returned value is not guaranteed to have the same sign as x
.
If the returned value is zero, it will have the same sign as x
.
Declarations
- C++23
- C++11
// 1)
constexpr /* floating-point-type */
remainder ( /* floating-point-type */ x,
/* floating-point-type */ y );
// 2)
constexpr float remainderf( float x, float y );
// 3)
constexpr long double remainderl( long double x, long double y );
// 4)
template< class Arithmetic1, class Arithmetic2 >
/* common-floating-point-type */
constexpr remainder( Arithmetic1 x, Arithmetic2 y );
// 1)
float remainder ( float x, float y );
// 2)
double remainder ( double x, double y );
// 3)
long double remainder ( long double x, long double y );
// 4)
float remainderf( float x, float y );
// 5)
long double remainderl( long double x, long double y );
// 6)
template< class Arithmetic1, class Arithmetic2 >
/* common-floating-point-type */
remainder( Arithmetic1 x, Arithmetic2 y );
Parameters
x
, y
- floating-point or integer values
Return value
If successful, returns the IEEE floating-point remainder of the division x / y
as defined above.
If a domain error occurs, an implementation-defined value is returned (NaN where supported)
If a range error occurs due to underflow, the correct result is returned.
If y
is zero, but the domain error does not occur, zero is returned.
Error handling
Errors are reported as specified in math_errhandling.
Domain error may occur if y
is zero.
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
The current rounding mode has no effect. FE_INEXACT is never raised, the result is always exact.
- If
x
is ±∞ andy
is not NaN, NaN is returned and FE_INVALID is raised - If
y
is ±0 andx
is not NaN, NaN is returned and FE_INVALID is raised - If either argument is NaN, NaN is returned
Examples
#include <cfenv>
#include <cmath>
#include <iostream>
// #pragma STDC FENV_ACCESS ON
int main()
{
std::cout
<< "remainder(+5.1, +3.0) = "
<< std::remainder(5.1, 3) << '\n'
<< "remainder(-5.1, +3.0) = "
<< std::remainder(-5.1, 3) << '\n'
<< "remainder(+5.1, -3.0) = "
<< std::remainder(5.1, -3) << '\n'
<< "remainder(-5.1, -3.0) = "
<< std::remainder(-5.1, -3) << '\n';
// special values
std::cout
<< "remainder(-0.0, 1.0) = "
<< std::remainder(-0.0, 1) << '\n'
<< "remainder(5.1, Inf) = "
<< std::remainder(5.1, INFINITY) << '\n';
// error handling
std::feclearexcept(FE_ALL_EXCEPT);
std::cout
<< "remainder(+5.1, 0) = "
<< std::remainder(5.1, 0) << '\n';
if (fetestexcept(FE_INVALID))
std::cout
<< "FE_INVALID raised\n";
}
remainder(+5.1, +3.0) = -0.9
remainder(-5.1, +3.0) = 0.9
remainder(+5.1, -3.0) = -0.9
remainder(-5.1, -3.0) = 0.9
remainder(-0.0, 1.0) = -0
remainder(5.1, Inf) = 5.1
remainder(+5.1, 0) = -nan
FE_INVALID raised