                 }
             }
             set(newValue) {
+                // HACK: The definition of this inline function takes an inout reference to self, giving the optimizer a unique referencing guarantee.
+                //       This allows us to avoid excessive retain-release traffic around modifying enum values, and inlining the function then avoids the additional frame.
                 @inline(__always)
                 func apply(_ representation: inout _Representation, _ newValue: Int) -> _Representation? {
                     switch representation {

            }
        }

        @inlinable
        subscript(index: Index) -> UInt8 {
            get {
                switch self {

            }
        }

        @inlinable // This is @inlinable as trivially forwarding.
        var endIndex: Int {
            switch self {
            case .empty: return 0
