Since we require C++11, it should be possible to simplify this whole thing to an ```initializer_list``` assignment:
```c++
    m_map = { { 1.0f, 0.0f, 0.0f, 0.0f },
              { 0.0f, 1.0f, 0.0f, 0.0f },
              { 0.0f, 0.0f, 1.0f, 0.0f },
              { 0.0f, 0.0f, 0.0f, 1.0f } };