git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@23220 a592a061-630c-0410-9148-cb99ea01b6c8
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@23216 a592a061-630c-0410-9148-cb99ea01b6c8
random-access (i.e. O(log n)) to the n-th element in a list/set. Try it with 1000000 keys ... no problem. git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@23213 a592a061-630c-0410-9148-cb99ea01b6c8