let m = mat4x4(mat4x4(0.0f, 1.0f, 2.0f, 3.0f,
                      4.0f, 5.0f, 6.0f, 7.0f,
                      8.0f, 9.0f, 10.0f, 11.0f,
                      12.0f, 13.0f, 14.0f, 15.0f));

fn f() -> mat4x4<f32> {
    let m_1 = mat4x4(m);
    return m_1;
}