greater

Function Object

• Summary
• Data Type and Member Function Indexes
• Synopsis
• Description
• Warnings
• See Also

A binary function object that returns true if its first argument is greater than its second.

None

#include <functional>
template <class T>
struct greater : binary_function<T, T, bool> {
  bool operator() (const T&, const T&) const;
};

greater is a binary function object. Its operator() returns true if x is greater than y. You can pass a greater object to any algorithm that requires a binary function. For example, the transform algorithm applies a binary operation to corresponding values in two collections and stores the result of the function. greater would be used in that algorithm in the following manner:

vector<int> vec1;
vector<int> vec2;
vector<int> vecResult;
.
.
.
transform(vec1.begin(), vec1.end(),
          vec2.begin(), vecResult.begin(), greater<int>());

After this call to transform, vecResult(n) contains a 1 if vec1(n) was greater than vec2(n) or a 0 if vec1(n) was less than or equal to vec2(n).

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.

Function Objects