Attempt to define UITableViews more declaratively

TableViewDataSource.swift

//
//  TableViewDataSource.swift
//

import UIKit

//////////////////////////////
// Project code
//////////////////////////////

// MARK: -

/**
 This is how I want to define UITableViews. Each section only needs one type of reusable cell.
 
 This table view has two sections: One for string-based views, and one for color-based views.
 */

class MyStringAndColorTableView: UITableView {
    
    let stringValues = ["First", "Second"]
    let colorValues: [UIColor] = [.blue, .brown]
    
    init() {
        
        super.init(frame: .zero, style: .plain)
        
        let stringSection = TableViewSection(values: stringValues, reuseIdentifier: UILabel.reuseIdentifier) { (string, view) -> UIView in
            let label = view as? UILabel ?? UILabel()
            label.text = string
            return label
        }
        
        let colorSection = TableViewSection(values: colorValues, reuseIdentifier: UIView.reuseIdentifier) { (color, view) -> UIView in
            let view = view ?? UIView()
            view.backgroundColor = color
            return view
        }
        
        // Current error in Xcode: Heterogeneous collection literal could only be interred to '[Any]'; add explicit type annotation if this is intentional
        let sections = [stringSection, colorSection]
        
        // Current error in Xcode: Cannot convert value of type '[Any]' to expected argument type '[TableViewSection<Any>]'
        let dataSource = TableViewDataSource(sections: sections)
        
        self.dataSource = dataSource
    }
    
    required init?(coder aDecoder: NSCoder) {
        
        fatalError("init(coder:) has not been implemented")
    }
    
}

//////////////////////////////
// Library code
//////////////////////////////

// MARK: -

struct TableViewSection<GenericValue> {

    let values: [GenericValue]
    let reuseIdentifier: String
    let viewAt: (_ value: GenericValue, _ view: UIView?) -> UIView
}

// MARK: -

class TableViewDataSource: NSObject, UITableViewDataSource {
    
    // The crux of the problem: How to define an array whose content's types contain multiple different generics?
    var sections = [TableViewSection<Any>]()

    init(sections: [TableViewSection<Any>]) {

        self.sections = sections
    }

    // UITableViewDataSource

    func numberOfSections(in tableView: UITableView) -> Int {

        return sections.count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        let tableViewSection = sections[section]
        return tableViewSection.values.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
        let tableViewSection = sections[indexPath.section]
        let dequeuedCell = tableView.dequeueReusableCell(withIdentifier: tableViewSection.reuseIdentifier)
        let dequeuedView = (dequeuedCell as? TableViewCell)?.view ?? dequeuedCell
        
        let value = tableViewSection.values[indexPath.row]
        let view = tableViewSection.viewAt(value, dequeuedView)
        return view as? UITableViewCell ?? TableViewCell(view: view)
    }

}

// MARK: -

/**
 This convenience UITableViewCell subclass allows you to create cells from simple UIViews.
 */

class TableViewCell: UITableViewCell {

    var view: UIView

    init(view: UIView) {

        self.view = view

        super.init(style: .default, reuseIdentifier: type(of: view).reuseIdentifier)

        contentView.addSubview(view)
        // Pin edges of view to contentView via autolayout...
    }

    required init?(coder aDecoder: NSCoder) {

        fatalError("init(coder:) has not been implemented")
    }

}

// MARK: -

extension UIView {
    
    static var reuseIdentifier: String { return String(describing: self) }
 
}