As Free Pascal 2.6.4 distribution does not include generic tree implementation (there are some limitation of compiler), I use my own named FGLExt for different purposes.

Here are 2 files in repository:

• fglext.pas - implements TFPGTree, TFPGTreeNode and TFPGStack classes
• fglexttest.pas - some unit tests for it and use cases

As I know, Free Pascal 3.x will be more generic-friendly so the more usable implementation of TFPGTreeNode may be done.

Links:

• issue on FPC tracker: http://bugs.freepascal.org/view.php?id=2...
• related forum thread: http://forum.lazarus.freepascal.org/inde...