In https://github.com/nrc/r4cppp/blob/master/data-types.md an example is given of a Node class which refers to a parent node. It should be explained why that field is `Option<Rc<Node>>` rather than `Option<Box<Node>>`. Or - that it doesn't really matter.
This issue appears to be discussing a feature request or bug report related to the repository. Based on the content, it seems to be still under discussion. The issue was opened by eyalroz and has received 0 comments.