title: Pybind11: Passing a Python list to C-style array
body: <p>I would like to pass a Python list to a constructor which takes C-style arrays.
  How should that work. The problem is that the C-style array is essentially a pointer. Furthermore, the array has dimension n x n, i.e. it is a multi-dimensional array.</p>
  
  <pre><code>     PYBIND11_MODULE(matrix_class_bind, m){
           py::class_&lt;matrix_class&lt;double&gt;&gt;(m, "matrix_class")
           .def(py::init([](double x[3][3]){
            matrix_class&lt;double&gt; new_class(x);
            return new_class;}));
      }
  </code></pre>
  
  <p>On the python side it should be something like:</p>
  
  <pre><code>import matrix_class_bind as mcb    
  a = [[1,2,3], [3,4,5], [1,1,1]]
  mcb.matrix_class(a)
  </code></pre>