let device = Device()

print(device)     // prints for example "iPhone 6 Plus"

if device == .iPhone6Plus {
    // Do something
} else {
    // Do something else
}

...

if device.batteryState == .Full || device.batteryState >= .Charging(75) {
    print("Your battery is happy! 😊")
}

...

if device.batteryLevel >= 50 {
    install_iOS()
} else {
    showError()
}