NSDiffableDataSourceSnapshot reloadItems

ViewController.swift

import UIKit

class ViewController: UITableViewController {
    
    var things = [Thing]()
    var dataSource: UITableViewDiffableDataSource<Int, Thing>!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        things = [Thing(), Thing(), Thing(), Thing(), Thing()]
        
        dataSource = UITableViewDiffableDataSource<Int, Thing>(tableView: tableView, cellProvider: { tableView, indexPath, thing -> UITableViewCell? in
            let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") ?? UITableViewCell()
            cell.textLabel?.text = "\(thing.id)"
            return cell
        })
        
        tableView.dataSource = dataSource
        
        var snapshot = NSDiffableDataSourceSnapshot<Int, Thing>()
        snapshot.appendSections([0])
        snapshot.appendItems(things)
        dataSource.apply(snapshot)
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        if let data = try? JSONEncoder().encode(things) {
            let newThings = try! JSONDecoder().decode([Thing].self, from: data)
            
            print("Things: \(things)")
            print("New Things: \(newThings)")
            
            things = newThings
        }
        
        var snapshot = dataSource.snapshot()
        snapshot.reloadItems([things[2]])
        dataSource.apply(snapshot)
    }

    class Thing: Codable, Hashable, CustomStringConvertible {
        static func == (lhs: Thing, rhs: Thing) -> Bool {
            lhs.id == rhs.id
        }
        
        let id: UUID
        
        init() {
            id = UUID()
        }
        
        var description: String {
            return "Thing: \(id)"
        }
        
        func hash(into hasher: inout Hasher) {
            hasher.combine(id)
        }
    }
    
}

Crashes when reloading an item if Thing is a class and not a struct.