I am trying to create a CMakeLists.txt file for a project that requires Eigen. A complication is that I would like this CMake build to work in the cases where Eigen has been installed and when it has simply been unpacked into a directory tree (this is the way I normally use Eigen).
I have read this doc: https://eigen.tuxfamily.org/dox/TopicCMakeGuide.html But it appears to me that this approach works only for the installed case because Eigen3Config.cmake doesn't exist until Eigen is installed. On the other hand, the un-installed Eigen source tree contains the file FindEigen3.cmake which can be found by cmake find_package in module mode. But FindEigen3.cmake isn't copied to the directory tree by the installation process. As a consequence, my CMakeLists.txt file requires some rather convoluted logic to support both cases. Am I understanding the current situation correctly? Thanks.
