Eigen 3.4?

[kinh-nguyen]

I see mentions here about Eigen unsupported 3.4, but it seems TMB is still using RcppEigen that has not updated to Eigen 3.4 (as discussed here)

@jeffeaton
I updated Eigen/unsupported to version 3.4 and can now do (without further changes):

Originally posted by @kaskr in #357 (comment)

[kinh-nguyen]

Oh, I see the commit that updated Eigen to 3.4, but wonder why the slicing below does not work in TMB but works in cling that includes Eigen 3.4.0.

MatrixXi A = MatrixXi::Random(4,6);
cout << "Initial matrix A:\n" << A << "\n\n";
cout << "A(all,{4,2,5,5,3}):\n" << A(Eigen::placeholders::all,{4,2,5,5,3}) << "\n\n";