XFXFramework/include/System/Nullable.h

namespace System
{
	// Represents an object whose underlying type is a value type that can also be assigned null like a reference type.
	template <typename T>
	class Nullable
	{
	private:
		T* data;

	public:
		static const Nullable<T> Null;

		Nullable()
			: data(null)
		{
		}

		Nullable(const T& newData)
			: data(const_cast<T*>(&newData))
		{
		}

		Nullable(T const * const newData)
			: data(const_cast<T*>(newData))
		{
		}

		Nullable(const Nullable<T> &obj)
			: data(obj.data)
		{
		}

		bool HasValue() const { return (data != null); }
		T getValue() const { return *data; }

		operator T() const { return *data; }

		Nullable<T>& operator =(const T * newVal)
		{
			data = newVal;
			return *this;
		}

		Nullable<T>& operator =(const Nullable<T>& right)
		{
			if (right == *this)
				goto end;

			*data = *right.data;
		end:
			return *this;
		}
	};

	template <typename T>
	const Nullable<T> Nullable<T>::Null = Nullable<T>();
}