modulus


class template
<functional> 
template <class T> struct modulus;

Modulus function object class

This class defines function objects for the modulus arithmetic operation.

Generically, function objects are instances of a class with member function operator() defined. This member function allows the object to be used with the same syntax as a regular function call, and therefore it can be used in templates instead of a pointer to a function.

modulus has its operator() member defined such that it returns the remainder of dividing its first argument by the second (i.e., its modulus).

This class is derived from binary_function and is defined as:

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template <class T> struct modulus : binary_function <T,T,T> {
  T operator() (const T& x, const T& y) const
    {return x%y;}
};


Objects of this class can be used with some standard algorithms such as transform or accumulate.

Members

T operator() (const T& x, const T& y)
Member function returning x%y.


Example

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// modulus example
#include <iostream>
#include <functional>
#include <algorithm>
using namespace std;

int main () {
  int numbers[]={1,2,3,4,5};
  int remainders[5];
  transform ( numbers, numbers+5, remainders, bind2nd(modulus<int>(),2) );
  for (int i=0; i<5; i++)
	  cout << numbers[i] << " is " << (remainders[i]==1?"odd":"even") << "\n";
  return 0;
}


Output:

1 is odd
2 is even
3 is odd
4 is even
5 is odd


See also

plus Addition function object class (class template)
minus Subtraction function object class (class template)
multiplies Multiplication function object class (class template)
divides Division function object class (class template)
negate Negative function object class (class template)
equal_to Function object class for equality comparison (class template)
binary_function Binary function object base class (class template)