How do I check for availability of a symbol, rather than OS version, in Swift?

Question

I have code of the form

if #available(iOS 10.2, *) {
    device = AVCaptureDeviceType.builtInDualCamera
} else {
    device = AVCaptureDeviceType.builtInDuoCamera
}

Is

if #available(AVCaptureDeviceType.builtInDualCamera) {

... possible?

The latter expresses my intention better — if the value builtInDualCamera exists, use it. I couldn't care less whether it was introduced in iOS 10.1 or .2 or .3.