Ensure value in a Dictionary

In many cases, I need to get the value from a dictionary given a key (usually a string). I have the following helper class:

public class ObjectCache<T> {
    private var cache = [String: T]()

    subscript(name: String) -> T? {
        get { return cache[name] }
        set { cache[name] = newValue }
    }

    func get(_ name: String, with builder: () -> T?) -> T? {
        var obj = cache[name]
        if obj == nil {
            obj = builder()
            cache[name] = obj
        }
        return obj
    }
}

This saves much keyboard typing and avoid common errors of oversight. Like below:

let serviceURL = self.urlCache.get(name) { return comp.url }!

Now my question is - Does Swift provide some builtin functionality like this? I just hope I did not re-event the wheel.