FixedVectorWithIterators.h

#pragma once

#include <stdexcept>

using namespace std;

template <typename ELT>
class FixedVector {
private:
	int _length;
	ELT *_array;

public:
	// Iterator is a nested class within FixedVector<ELT>
	class Iterator {				// an iterator for the list
	public:
		ELT& get() {		// reference to the element
			return _vector->get(_index);
		}
		ELT& operator*() {		// reference to the element
			return _vector[index];
		}
		bool operator==(const Iterator& p) const {	// compare positions
			return _index == p._index;
		}
		bool operator!=(const Iterator& p) const {
			return _index != p._index;
		}
		Iterator& operator++() {		// move to next position
			_index++; return *this;
		}
		friend class FixedVector;			// give FixedVector access
	private:
		int _index;					// index to current element
		FixedVector<ELT> *_vector;	// pointer to the data structure
		Iterator(int u, FixedVector<ELT> *fixedArray) {		// constructor from int
			 _index = u;
			 _vector = fixedArray;
		}
	};

public:
	// length copies of default_value
	FixedVector(int length) {
		if (length < 0) throw invalid_argument("length < 0");
		_length = length;
		_array = new ELT[length];
	}

	// default constructor: empty vector
	FixedVector() {
		_length = 0;
		_array = new ELT[0];
	}

	// copy constructor
	FixedVector(const FixedVector& a) {
		_length = a._length;
		_array = new ELT[length];
		for (int i = 0; i < length; i++)
			_array[i] = a._array[i];
	}

	~FixedVector() { delete[] _array; }

	int length() { return _length; }

	bool is_empty() { return (_length == 0); }

	ELT& get(int index) {
		if ((index < 0) || (index >= _length)) throw range_error("index out of bounds");
		return _array[index];
	}

	void set(int index, ELT value) {
		if (is_empty()) throw invalid_argument("array is empty");
		if ((index < 0) || (index >= _length)) throw range_error("index out of bounds");
		_array[index] = value;
	}

	ELT& operator[](int index) {
		if ((index < 0) || (index >= _length)) throw range_error("index out of bounds");
		return get(index);
	}

	Iterator begin() {		// beginning position is first item
		return Iterator(0, this);
	}

	Iterator end() {		// beginning position is first item
		return Iterator(_length, this);
	}

};