#include <algorithm>
#include <list>
#include <set>
#include <string>
#include <iostream.h>
	
class OurFriends {
public:
    bool operator()( const string& str ) {
	   return ( friendset.count( str ))
		    ? true : false;
    }
	    
    static void 
    FriendSet( const string *fs, int count ) {
	   copy( fs, fs+count, 
		 inserter( friendset, friendset.end() )); 
    }
	
private:
    static set< string, less<string>, allocator > friendset;
};
	
set< string, less<string>, allocator > OurFriends::friendset;

int main() 
{
    string Pooh_friends[] = { "Piglet", "Tigger", "Eyeore"  };
    string more_friends[] = { "Quasimodo", "Chip", "Piglet" };
    list<string,allocator> lf( more_friends, more_friends+3 );

    // populate a list of pooh friends
    OurFriends::FriendSet( Pooh_friends, 3 );
	
    list<string,allocator>::iterator our_mutual_friend;
    our_mutual_friend = find_if( lf.begin(), lf.end(), OurFriends());
	
    // generates: 
    //   Ah, imagine our friend Piglet is also a friend of Pooh.
    if ( our_mutual_friend != lf.end() ) 
         cout << "Ah, imagine our friend "
	      << *our_mutual_friend
	      << " is also a friend of Pooh.\n";
	
    return 0;
}