safeAreaInsets.top と status bar のメモ ref: http://qiita.com/MTattin/items/224746049bbd849c49f4

file0.swift

///
/// Safe Area Insets
///
var SAFE: UIEdgeInsets {
    get {
        if #available(iOS 11.0, *) {
            if let insets = AppDelegate?.window?.safeAreaInsets {
                return insets
            }
        }
        return UIEdgeInsets.zero
    }
}