If you try to compile Eigen together with some other library using the C99 complex standard (like MathGL, see here: https://groups.google.com/d/msg/mathgl/e13HvSB_nyg/xiuCw0teAgAJ) weird messages/compilation errors appear.
We've spotted that it's related to the C99 complex standard defining "I" as an special constant for the imaginary unit. This interferes with the lines 112-129 in "/src/Core/solveTriangular.h". Renaming this variables probably fixes this problem.
-- GitLab Migration Automatic Message --
This bug has been migrated to gitlab.com's GitLab instance and has been closed from further activity.
You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.com/libeigen/eigen/issues/1113.