// Demonstrating use of STL's predicate templates and adaptors

#include <list.h>
#include <algo.h>
#include <assert.h>

void show_int (int x)
{
  cout << x << " ";
}

int main()
{
  cout << "Demonstrating Function Objects with lists." << endl;

  list<int> list2;

  // populating the list using "push_back"
  list2.push_back(89);
  list2.push_back(99);
  list2.push_back(89);
  list2.push_back(69);
  list2.push_back(64);
  list2.push_back(89);
  list2.push_back(89);
  list2.push_back(49);

  cout << "LIST2 Elements: " ;
  for_each(list2.begin(), list2.end(), show_int);
  cout << endl;

  // following example shows how to use pre-existing STL
  // templates "greater" and adaptor "bind2nd" to define a
  // predicate which returns true when the parameter it
  // is given is greater than 40...
  // bind2nd is called a function ADAPTOR because it 
  // converts a binary comparison to a unary comparison by
  // fixing the 2nd parameter to some constant value...
  cout << "Count of numbers > 40: " 
       << count_if(list2.begin(), list2.end(), 
		   bind2nd(greater<int>(), 40))
	 << endl;

  // look for for items > 80
  cout << "Count of numbers > 80: " 
       << count_if(list2.begin(), list2.end(), 
		   bind2nd(greater<int>(), 80))
	 << endl;
  
  // replace numbers less than 80 using "less"  and bind2nd
  // as before...
  replace_if(list2.begin(), list2.end(), bind2nd(less<int>(), 80), 25);
  cout << "LIST2 Elements (after replacement): " ;
  for_each(list2.begin(), list2.end(), show_int);
  cout << endl;

}