less_equal

     Function Object

Binary function object that returns true if its first argument is less than or equal to its second

Contents

• Synopsis
• Description
• Interface
• Warning
• See Also

#include<functional>

template <class T>
struct less_equal : public binary_function<T, T, bool>;

less_equal is a binary function object. Its operator() returns true if x is less than or equal to y. You can pass a less_equal object to any algorithm that requires a binary function. For example, the sort algorithm can accept a binary function as an alternate comparison object to sort a sequence. less_equal would be used in that algorithm in the following manner:

vector<int> vec1;

.
.
.
sort(vec1.begin(), vec1.end(),less_equal<int>());

After this call to sort, vec1 will be sorted in ascending order.

template <class T>

struct less_equal : binary_function<T, T, bool> {
 typedef typename binary_function<T, T, bool>::second_argument_type 
                                               second_argument_type;
  typedef typename binary_function<T, T, bool>::first_argument_type 
                                                first_argument_type;
  typedef typename binary_function<T, T, bool>::result_type 
                                                result_type;
  bool operator() (const T&, const T&) const;
};

If your compiler does not support default template parameters, then you need to always supply the Allocator template argument. For instance, you'll have to write :

vector<int, allocator>

instead of

vector<int>

binary_function, Function Objects