// pointers06.cpp
#include <map>
#include <vector>

typedef unsigned int pixelValue;
typedef std::pair<int, int> pixelIndex;

class Undo
{
public:
	Undo(pixelIndex startOfLine, pixelIndex endOfLine, const std::vector<std::vector<pixelValue> >& bitmap)
	{
		// store old values on line
	}

	void Restore(std::vector<std::vector<pixelValue> >& bitmap) const
	{
		// restore old values in correct places
	}

private:
	std::map<pixelIndex, pixelValue> m_OldValue;
};