greater


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

Function object class for greater-than inequality comparison

This class defines function objects for the "greater than" inequality comparison 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.

greater has its operator() member defined such that it returns true if its first argument compares greater than the second one using operator>, and false otherwise.

This class is derived from binary_function and is defined as:

1
2
3
4
 
template <class T> struct greater : binary_function <T,T,bool> {
  bool operator() (const T& x, const T& y) const
    {return x>y;}
};


Objects of this class can be used with some standard algorithms such as sort, merge or lower_bound.

Members

T operator() (const T& x, const T& y)
Member function returning the result of the comparison x>y.


Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
 
// greater example
#include <iostream>
#include <functional>
#include <algorithm>
using namespace std;

int main () {
  int numbers[]={20,40,50,10,30};
  sort (numbers, numbers+5, greater<int>() );
  for (int i=0; i<5; i++)
    cout << numbers[i] << " ";
  cout << endl;
  return 0;
}


Output:

50 40 30 20 10


See also

equal_to Function object class for equality comparison (class template)
not_equal_to Function object class for non-equality comparison (class template)
less Function object class for less-than inequality comparison (class template)
greater_equal Function object class for greater-than-or-equal-to comparison (class template)
less_equal Function object class for less-than-or-equal-to comparison (class template)
binary_function Binary function object base class (class template)