Swift, Concurrency: Universal escape hatch from Swift structured concurrency #swift-concurrency

UncheckedSendableCompletion.swift

/// Universal escape hatch.
///
/// [Original source](https://stackoverflow.com/a/78894560/4370543)
struct UncheckedSendable<T>: @unchecked Sendable {
	let unwrap: T
	init(_ value: T) { unwrap = value}
}

// A sample of usage with `SendBirdCalls` iOS SDK. Where it was impossible to have async version (was a crash).

// MARK: - Process with CXProvider
extension CXCallManager {
  /// Specific escape hatch.
  struct UncheckedSendableCompletion: @unchecked Sendable {
    let unwrap: (Error?) -> Void
    init(_ value: @escaping (Error?) -> Void) { unwrap = value }
  }
  
  /// (!) Completion version instead of async.
  func reportIncomingCall(with callID: UUID, update: CXCallUpdate, completion: UncheckedSendableCompletion) {
    self.provider.reportNewIncomingCall(with: callID, update: update) { (error) in
      completion.unwrap(error)
    }
  }
  
  func reportIncomingCall(with callID: UUID, update: CXCallUpdate) async throws {
    try await self.provider.reportNewIncomingCall(with: callID, update: update)
  }
  
  func endCall(for callId: UUID, endedAt: Date, reason: DirectCallEndResult) {
    guard let endReason = reason.asCXCallEndedReason else { return }
    self.provider.reportCall(with: callId, endedAt: endedAt, reason: endReason)
  }
  
  func connectedCall(_ call: DirectCall) {
    let connectedAt = Date(timeIntervalSince1970: Double(call.startedAt) / 1000)
    self.provider.reportOutgoingCall(with: call.callUUID!, connectedAt: connectedAt)
  }
}