Swift 5.7 RegexBuilder: Nested TryCapture - transform / Mapping Output?

Question

Here in this example I tried to capture two Int values and then capture them together as a struct. This gives a "Thread 1: signal SIGABRT" error.

(NOTE: I know that my example could be fixed by simply not nesting the Captures and handling the pattern matching differently. This is just simplified example code for the sake of this question.)

let intCapture = Regex {
    TryCapture(as: Reference(Int.self)) {
        OneOrMore(.digit)
    } transform: { result in
        return Int(result)
    }
}

let mainPattern = Regex {
    TryCapture(as: Reference(Floor.self)) {
        "floor #: "
        intCapture
        " has "
        intCapture
        " rooms"
    }transform: { ( stringMatch, floorInt, roomInt )  in
        return Floor(floorNumber: floorInt, roomCount: roomInt)
    }
}

struct Floor {
    let floorNumber: Int
    let roomCount: Int
}

let testString = "floor #: 34 has 25 rooms"

let floorData = testString.firstMatch(of: mainPattern)

After looking into it, I found that in the mainPattern's 'transform' the 'floorInt' and 'roomInt' are what is causing the problem.

The funny part is that when you look at the 'Quick Help'/Option+click, it shows that they are both type Int! It knows what is there but you are not able to capture it!

Further, when I erase one of them, let's say 'floorInt', it gives this error:

Contextual closure type '(Substring) throws -> Floor?' expects 1 argument, but 2 were used in closure body

So really, even though for SOME reason it does know that there are two captured Int values there, it doesn't let you access them for the sake of the transform.

Not deterred, I was helped out in another question by a very helpful user who pointed me to the Evolution submission where they mentioned a .mapOutput, but sadly it seems this particular feature was never implemented!

Is there no real way to create a new transformed value from nested transformed values like this? Any help would be greatly appreciated.