// There is a standard vector class in C++, but it is based on a
// template, not on polymophism.

#include <iostream>
#include <vector>
#include <list>
#include <string>

using namespace std;

// Generic printing function.  Note:  This function can print the contents
// of any object which implements the iterator pattern used by the standard
// library, and whose members cout knows how to print.
template <typename CollectType>
void print_col(CollectType &v)
{
	int m = 0;
	for(auto i = v.begin(); i != v.end(); ++i) {
		if(i != v.begin()) cout << " ";
		cout << *i;
	}
}

void craziness();

int main()
{
	// Put some stuff in a vector of strings.
	vector<string> v = { "How", "are", "you", "today?" };
	v.insert(v.begin() + 3, "doing");
	print_col(v);
	cout << endl;

	// Put some stuff in a list.
	list<int> q;
	q.push_back(45);
	q.push_back(3);
	q.push_front(-34);
	q.push_back(75);
	q.push_front(9);
	print_col(q);
	cout << endl;

	// And try a string, which also offers the iterator pattern.
	string mars = "Hello, Mars!";
	print_col(mars);
	cout << endl;

	// See below.  If you dare.
	craziness();
}

// ==== Consider the rest of this file optional material ====

/*
 * This class represents a range that can be iterated through.  Not good for
 * much, though I suppose it could be the start of something marginally
 * useful.
 */
class Range {
public:
	// Range of numbers is first to last.
	Range(int first, int last) {
		set(first, last);
	}

	// Change the range.
	void set(int first, int last) {
		m_first = first;
		m_last = last;
	}
	
	// This is the iterator type, which is really just a
	// wrapper for int.  This class uses the operator keyword which
	// allows a C++ programmer to define methods which give the meaning
	// of certain operators.  It should be used sparingly, but some are
	// required to create an iterator.
	class iterator {
	public:
		iterator(int i) { m_i = i; }

		// This defines the meaning of the ++ operator on an iterator.
		iterator operator++() {
			++m_i;
			return *this;
		}

		// Here's what * does to an iterator.  (Just returns
		// the integer.)
		int operator*() const { return m_i; }

		// Define how to compare.
		int operator!=(iterator i) const { return m_i != i.m_i; }
	private:
		int m_i;
	};

	// Begin and end.
	iterator begin() { return iterator(m_first); }
	iterator end() { return iterator(m_last + 1); }
private:
	// The start and end of the range.
	int m_first, m_last;
};

void craziness()
{
	Range ct(1,10);
	print_col(ct);
	cout << endl;

	ct.set(6,18);
	print_col(ct);
	cout << endl;
}