[eigen] Passing result of block() as non-const reference-to-matrix? |

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Hello,
Today I found, to my surprise, that passing the result of a Matrix::block() method to a function that takes a reference to an Eigen::Matrix doesn't seem to work. The program (which doesn't compile) demonstrates the problem.
I know that it /is/ possible to pass the result of a Matrix::block() const call to a const reference to an Eigen::Matrix. Is it intentional that the non-const version of this does not work?
Any help would be greatly appreciated.
Regards, Sidney
/////////////////////// code fragment starts here
#include <Eigen/Core>
void incrementBottomRight(Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic> & m)
{
m(m.rows() - 1, m.cols() - 1) += 1.0;
}
int main()
{
Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic> testMatrix(3, 3);
// This works fine
incrementBottomRight(testMatrix);
// This gives a compiler error
incrementBottomRight(testMatrix.block(0, 0, 2, 2));
std::cout << testMatrix << std::endl;
return 0;
}