SGMatrix instances are always created on the stack. 
m_bound=SGMatrix();
Also, SGMatrix instances are never stored as pointers (heap), but directly (stack)
```SGMatrix<T> m=SGMatrix<T>(10,10);```
Also no need to reference them, that all done automagically.
And when you SG_ADD them, you do not need to cast to anything (see other Shogun classes which have members of SGMatrix or SGVector