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cplusplus.com   C++ : Reference : STL Containers : set : value_comp
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· set::value_comp

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set::value_comp public member function
value_compare value_comp ( ) const;

Return comparison object

Returns the comparison object associated with the container, which can be used to compare two elements of the container.

This comparison object is set on object construction, and may either be a pointer to a function or an object of a class with a function call operator. In both cases it takes two arguments of the same type as the container elements, and returns true if the first argument is considered to go before the second in the strict weak ordering the object defines, and false otherwise.

In set containers, the element values are the keys themselves, therefore value_comp and its sibling member function key_comp both return the same.

Parameters

none

Return value

The comparison object.
set::value_compare is a member type defined to Compare, which is the second template parameter in the set class template.

Example

// set::value_comp
#include <iostream>
#include <set>
using namespace std;

int main ()
{
  set<int> myset;
  set<int>::value_compare mycomp;
  set<int>::iterator it;
  int i,highest;

  mycomp = myset.value_comp();

  for (i=0; i<=5; i++) myset.insert(i);

  cout << "myset contains:";

  highest=*myset.rbegin();
  it=myset.begin();
  do {
    cout << " " << *it;
  } while ( mycomp(*it++,highest) );

  cout << endl;

  return 0;
}

Output:

myset contains: 0 1 2 3 4 5

Complexity

Constant.

See also

set::key_comp Return comparison object (public member function)
set::find Get iterator to element (public member function)
set::count Count elements with a specific key (public member function)
set::lower_bound Return iterator to lower bound (public member function)
set::upper_bound Return iterator to upper bound (public member function)

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