Using C++ using: What am I doing wrong here? - c++11

Question

The following code doesn't compile on the latest Microsoft Visual Studio. Could someone enlighten me on what I'm doing wrong here?
#include <iostream>
#include <iomanip>
#include <array>
template <typename T, std::size_t M, std::size_t N>
using Matrix = std::array<T, M * N>;
template <typename T, std::size_t M, std::size_t N>
std::ostream &operator<<(std::ostream &os, const Matrix<T, M, N> &matrix)
{
for (auto i = 0; i < M; ++i)
{
for (auto j = 0; j < N; ++j)
{
os << std::setw(5) << matrix[i * N + j];
}
os << std::endl;
}
return os;
}
int main(int argc, const char * const argv[])
{
Matrix<float, 2, 3> matrix{
1.1f, 1.2f, 1.3f,
2.1f, 2.2f, 2.3f
};
std::cout << matrix << std::endl;
return 0;
}
Here is a snapshot of the compiler error:
1>main.cpp(30): error C2679: binary '<<': no operator found which takes a right-hand operand of type 'std::array<T,6>' (or there is no acceptable conversion)
1> with
1> [
1> T=float
1> ]
Edit:
The following code works though:
#include <iostream>
#include <iomanip>
#include <array>
template <typename T, std::size_t M, std::size_t N>
using Matrix = std::array<std::array<T, N>, M>;
template <typename T, std::size_t M, std::size_t N>
std::ostream &operator<<(std::ostream &os, const Matrix<T, M, N> &matrix)
{
for (auto row : matrix)
{
for (auto element : row)
{
os << std::setw(5) << element;
}
os << std::endl;
}
return os;
}
int main(int argc, const char * const argv[])
{
Matrix<float, 2, 3> matrix{
1.1f, 1.2f, 1.3f,
2.1f, 2.2f, 2.3f
};
std::cout << matrix << std::endl;
return 0;
}

Answer 1

Bearing in mind #dyp's comment what you have to do here is to create the new type instead of alias that will have 2 independent params.
So you just use aggregation including actual data as a field, like:
template <typename T, std::size_t M, std::size_t N>
class Matrix
{
private:
std::array<T, M * N> _data;
template <typename T1, std::size_t M1, std::size_t N1> friend std::ostream &operator<<(std::ostream &os, const Matrix<T1, M1, N1> &matrix);
public:
template <typename...Args>
Matrix(Args... args):
_data{{std::forward<Args>(args)...}}
{}
};