// LBJSON enum properties int, double, bool, string, number, array and dictionary returns the associated values or nil
// Instead of casting you can use optional chaining.

if let posts = LBJSON(object: [["key":"Value"]]) {
    var post = posts.array?.first?.dictionary?["key"]?.string
}

// With @dynamicMemberLookup
if let posts = LBJSON(object: [["key":"Value"]]) {
    var post = posts.array?.first?.key?.string
}