mult_load.rs

use std::collections::HashMap;

struct Database {
    objects: HashMap<String, Object>,
}

enum Object {
    Tree,
    Commit { tree_id: String },
}

impl Database {
    fn load(&mut self, object_id: &str) -> &Object {
        self.objects
            .get(object_id)
            .expect("did not find object")
    }

    fn load_tree(&mut self, object_id: &str) -> &Object {
        match self.load(object_id) {
            Object::Tree => &Object::Tree,
            Object::Commit { tree_id } => self.load(&tree_id),
        }
    }
}

fn main() {}