Ordered lists

Ordered lists have the same member functions as unordered lists, but elements are inserted in some (user-defined) order. Because some ordering is required, you have to provide member functions to enforce an ordering if you want to use your own elements in an ordered list. These functions are operator< and operator==. Some other `external' functions has to be provided also to print an element to a stream, see the operator<< in the example.

The example:

// olist.cc

#include <hush/list.h>
#include <iostream.h>


// define our own class which can be used in the ordered list
class myclass
{
public:
    myclass(int i) { i_ = i; }
    int value() const { return i_; }
    int operator<(const myclass& m) const { return (i_ < m.value()); }
    int operator==(const myclass& m) const { return (i_ == m.value()); }

private:
    int i_;
};

// you MUST define a stream-operator for your own class (but it's only used
// when you evoke 'print' on an ordered list):
ostream& operator<<(ostream& os, const myclass& mc)
{
    os << mc.value();
    return os;
}

int main()
{
    myclass a(27), b(3), c(72);
    olist<myclass> l1;                  // create an ordered list with
                                        // elements of our own class

    l1.insert(&a);                      // add elements in unsorted order
    l1.insert(&b);
    l1.insert(&c);

    iter<myclass> mciter = l1;
    myclass* mcptr = 0;

    while (mcptr = mciter())
    {
        cout << "item = " << mcptr -> value() << endl;
    }

    l1.print(cout);                     // print the entire list on cout,
                                        // great for debugging

    return 0;
}