Describe the bug

I recently run into compilation problem with this piece of code:

Eigen::Matrix<double, -1, -1, Eigen::RowMajor> V;
Eigen::Matrix<int, -1, -1, Eigen::RowMajor> F;
igl::readMSH(argv[1], V, F);

With error

error: invalid initialization of non-const reference of type 'Eigen::MatrixXd& {aka Eigen::Matrix<double, -1, -1>&}' from an rvalue of type 'Eigen::MatrixXd {aka Eigen::Matrix<double, -1, -1>}'

If I remove the option Eigen::RowMajor, it compiles fine.

Platform

• Windows
• macOS
• Linux

This is a piece of old code and it compiled fine before. I am on GCC 5.4 with the libigl built-in Eigen. Igl is up-to-date with SHA dda197248e855c13bfac3d6e26b80be75e030ea1.