less_equal

Function Object

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• Data Type and Member Function Indexes
• Synopsis
• Description
• Interface
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A binary function object that returns true if its first argument is less than or equal to its second.

None

#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 is sorted in ascending order.

template <class T>
struct less_equal : binary_function<T, T, bool> {
  bool operator() (const T&, const T&) const;
};

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

vector<int, allocator<int> >

instead of

vector<int>

If your compiler does not support namespaces, then you do not need the using declaration for std.

binary_function, Function Objects