#include <iostream>
#include <stdexcept>

// Beispiel für Templates, Operatorüberladung und Ausnahmen

using std::cout;
using std::endl;
using std::ostream;
using std::runtime_error;

// Template mit Standardwerten/-typen
template<typename T = int, unsigned N = 10> class Array
{
	public:
		Array() : arr() {}

		T& operator [](unsigned i)
		{
			if (i >= N)
			{
				throw std::runtime_error("out of range");
			}
			return arr[i];
		}

		T const& operator [](unsigned i) const { return const_cast<Array&>(*this)[i]; }

	private:
		T arr[N];
};

/* Überladener Operator ist ein Template, damit er für beliebige Array<T, N>
 * verwendet werden kann */
template<typename T, unsigned N> ostream& operator <<(ostream& o, Array<T, N> const& a)
{
	char sep = '(';
	for (unsigned i = 0; i != N; ++i)
	{
		o << sep << a[i];
		sep = ',';
	}
	o << ')';
}

int main()
{
	try
	{
		Array<> a;
		a[10] = 23;
		Array<> const& b = a;
		cout << b << endl;

		Array<Array<float, 2>, 5> c;
		cout << c << endl;
	}
	catch (std::runtime_error const& e)
	{
		std::cerr << "error: " << e.what() << std::endl;
	}
	catch (...)
	{
		std::cerr << "an error occurred" << endl;
	}
}