Similar to bug 551, Eigen 3.2.5 fails to compile in Eigen/src/Core/Assign.h when checking pointer alignment. The fix could be something like,
Although there might be smarter ways to check alignment. I hadn't thought exhaustively about the best way to do it.
Thanks for the report. Fixed in 3.2 and devel:
We should probably add some unit-tests with custom Index types, but since this is a "sail at own risk"-feature anyways, it's not too urgent.