Currently learning Swift (in Xcode specifically), and this seemingly very simple operation isn’t working. I’m not sure what I’m doing wrong (simplified code):

var taps: Int = 0

var body: some View {
    Button(action: { taps += 1 }) { /* ... */ } // Left side of mutating operator isn't mutable: 'self' is immutable
}

I’ve tried a few variations of this, including taps = taps + 1, which didn’t work for the same reason. My understanding is that in Swift, var is mutable, so what’s wrong here?