Method swap

dependence/eigen-3.4.0/Eigen/src/SparseCore/SparseMatrix.h:737–745

Swaps the content of two sparse matrices of the same type. * This is a fast operation that simply swaps the underlying pointers and parameters. */

    /** Swaps the content of two sparse matrices of the same type.
      * This is a fast operation that simply swaps the underlying pointers and parameters. */
    inline void swap(SparseMatrix& other)
    {
      //EIGEN_DBG_SPARSE(std::cout << "SparseMatrix:: swap\n");
      std::swap(m_outerIndex, other.m_outerIndex);
      std::swap(m_innerSize, other.m_innerSize);
      std::swap(m_outerSize, other.m_outerSize);
      std::swap(m_innerNonZeros, other.m_innerNonZeros);
      m_data.swap(other.m_data);
    }

    /** Sets *this to the identity matrix.
      * This function also turns the matrix into compressed mode, and drop any reserved memory. */