UIFont extension for UIFontTextStyle and UIFontWeight

UIFont++.swift

import UIKit

extension UIFont {
    
    enum TextStyle: String {
        
        case title1
        case title2
        case title3
        case headline
        case subheadline
        case body
        case callout
        case footnote
        case caption1
        case caption2
        
        var rawValue: String {
            let capitalizedString = "\(self)".capitalized
            return "UICTFontTextStyle\(capitalizedString)"
        }
        
    }
    
    enum Weight {
        
        case ultraLight
        case thin
        case light
        case regular
        case medium
        case semibold
        case bold
        case heavy
        case black
        
        var floatValue: CGFloat {
            switch self {
            case .thin:       return UIFontWeightThin
            case .light:      return UIFontWeightLight
            case .ultraLight: return UIFontWeightUltraLight
            case .black:      return UIFontWeightBlack
            case .regular:    return UIFontWeightRegular
            case .bold:       return UIFontWeightBold
            case .medium:     return UIFontWeightMedium
            case .semibold:   return UIFontWeightSemibold
            case .heavy:      return UIFontWeightHeavy
            }
        }
        
    }

    class func preferredFont(for textStyle: UIFont.TextStyle) -> UIFont {
        return preferredFont(forTextStyle: textStyle.rawValue)
    }
    
    class func systemFont(ofSize size: CGFloat, weight: UIFont.Weight) -> UIFont {
        return systemFont(ofSize: size, weight: weight.floatValue)
    }
    
    class func monospacedDigitSystemFont(ofSize fontSize: CGFloat, weight: UIFont.Weight) -> UIFont {
        return monospacedDigitSystemFont(ofSize: fontSize, weight: weight.floatValue)
    }
    
    @available(iOS 10.0, *)
    class func preferredFont(for textStyle: UIFont.TextStyle, compatibleWith traitCollection: UITraitCollection?) -> UIFont {
        return preferredFont(forTextStyle: textStyle.rawValue, compatibleWith: traitCollection)
    }
    
}