class template

std::minus

<functional>
template <class T> struct minus;
Subtraction function object class
This class defines function objects for the subtraction 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.

minus has its operator() member defined such that it returns the result of subtracting its second argument from its first argument.

This class is derived from binary_function and is defined as:

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template <class T> struct minus : 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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// minus example
#include <iostream>
#include <functional>
#include <numeric>
using namespace std;

int main () {
  int numbers[]={10,20,30};
  int result;
  result = accumulate (numbers, numbers+3, 100, minus<int>() );
  cout << "The result of 100-10-20-30 is " << result << ".\n";
  return 0;
}


Output:

The result of 100-10-20-30 is 40.

See also