I am very sorry that I brought up so stupid a question, but I DID not find this file in 3.0.5 version.
I need this file because I need "ConjugateGradient< _MatrixType, _UpLo, _Preconditioner >", which, according to
http://eigen.tuxfamily.org/dox-devel/gr ... odule.html
is in <Eigen/IterativeLinearSolvers>
I need "ConjugateGradient< _MatrixType, _UpLo, _Preconditioner >" because CGAL needs it.
I need CGAL because I need to do a project.
I need to do this project because my boss needs me to do so.
So, is there any idea how can I work around it?
Many thanks!

You need the devel or least the alpha-2 version.