//.h
template <class T, int NumRows, int NumCols>
class McMatrix
{
public:
    template <int OthCols>
    McMatrix<T,NumRows,OthCols> Multiply(McMatrix<T,NumCols,OthCols> toMult);
};


//.cpp
template <class T, int NumRows, int NumCols>  template <int OthCols>
McMatrix<T,NumRows,OthCols> McMatrix<T,NumRows,NumCols>::Multiply(McMatrix<T,NumCols,OthCols> toMult);
{
    McMatrix<T,NumCols,OthCols> product;

    return product;
}