font+rounded.swift

extension Font {
    static func rounded(_ style: Font.TextStyle = .body, weight: Font.Weight = .semibold) -> Font {
        return .system(size: style.size, weight: weight, design: .rounded)
    }
}

extension Font.TextStyle {
    var size: CGFloat {
        switch self {
        case .largeTitle: return 60
        case .title: return 48
        case .title2: return 34
        case .title3: return 24
        case .headline, .body: return 18
        case .subheadline, .callout: return 16
        case .footnote: return 14
        case .caption, .caption2: return 12
        @unknown default:
            return 8
        }
    }
}

            Text("Hello, world!")
                .font(.rounded())