Why does Task.init(executorPreference:priority:operation:) consume the taskExecutor?

Using Swift
1

While Task.detached(executorPreference:priority:operation:) does not consume the taskExecutor , Task.init(executorPreference:priority:operation:) does consume it.

What causes this difference?

@available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
extension _Concurrency.Task where Failure == Swift.Never {
  #if compiler(>=5.3) && $SendingArgsAndResults
  @discardableResult
  @_alwaysEmitIntoClient public init(executorPreference taskExecutor: consuming (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: sending @escaping () async -> Success) {
    guard let taskExecutor else {
      self = Self.init(priority: priority, operation: operation)
      return
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: true,
      inheritContext: true, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    self._task = task
  }
  #else
  @discardableResult
  @_alwaysEmitIntoClient public init(executorPreference taskExecutor: consuming (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: @escaping () async -> Success) {
    guard let taskExecutor else {
      self = Self.init(priority: priority, operation: operation)
      return
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: true,
      inheritContext: true, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    self._task = task
  }
  #endif
}
@available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
extension _Concurrency.Task where Failure == any Swift.Error {
  #if compiler(>=5.3) && $SendingArgsAndResults
  @discardableResult
  @_alwaysEmitIntoClient public init(executorPreference taskExecutor: consuming (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: sending @escaping () async throws -> Success) {
    guard let taskExecutor else {
      self = Self.init(priority: priority, operation: operation)
      return
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: true,
      inheritContext: true, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    self._task = task
  }
  #else
  @discardableResult
  @_alwaysEmitIntoClient public init(executorPreference taskExecutor: consuming (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: @escaping () async throws -> Success) {
    guard let taskExecutor else {
      self = Self.init(priority: priority, operation: operation)
      return
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: true,
      inheritContext: true, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    self._task = task
  }
  #endif
}
@available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
extension _Concurrency.Task where Failure == Swift.Never {
  #if compiler(>=5.3) && $SendingArgsAndResults
  @discardableResult
  @_alwaysEmitIntoClient public static func detached(executorPreference taskExecutor: (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: sending @escaping () async -> Success) -> _Concurrency.Task<Success, Failure> {
    guard let taskExecutor else {
      return Self.detached(priority: priority, operation: operation)
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: false,
      inheritContext: false, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    return Task(task)
  }
  #else
  @discardableResult
  @_alwaysEmitIntoClient public static func detached(executorPreference taskExecutor: (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: @escaping () async -> Success) -> _Concurrency.Task<Success, Failure> {
    guard let taskExecutor else {
      return Self.detached(priority: priority, operation: operation)
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: false,
      inheritContext: false, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    return Task(task)
  }
  #endif
}
@available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
extension _Concurrency.Task where Failure == any Swift.Error {
  #if compiler(>=5.3) && $SendingArgsAndResults
  @discardableResult
  @_alwaysEmitIntoClient public static func detached(executorPreference taskExecutor: (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: sending @escaping () async throws -> Success) -> _Concurrency.Task<Success, Failure> {
    guard let taskExecutor else {
      return Self.detached(priority: priority, operation: operation)
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: false,
      inheritContext: false, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    return Task(task)
  }
  #else
  @discardableResult
  @_alwaysEmitIntoClient public static func detached(executorPreference taskExecutor: (any _Concurrency.TaskExecutor)?, priority: _Concurrency.TaskPriority? = nil, operation: @escaping () async throws -> Success) -> _Concurrency.Task<Success, Failure> {
    guard let taskExecutor else {
      return Self.detached(priority: priority, operation: operation)
    }
     
    let flags = taskCreateFlags(
      priority: priority, isChildTask: false, copyTaskLocals: false,
      inheritContext: false, enqueueJob: true,
      addPendingGroupTaskUnconditionally: false,
      isDiscardingTask: false)

#if $BuiltinCreateAsyncTaskOwnedTaskExecutor
    let (task, _) = Builtin.createTask(
      flags: flags,
      initialTaskExecutorConsuming: taskExecutor,
      operation: operation)
#else
    let executorBuiltin: Builtin.Executor =
      taskExecutor.asUnownedTaskExecutor().executor
    let (task, _) = Builtin.createAsyncTaskWithExecutor(
      flags, executorBuiltin, operation)
#endif
    return Task(task)
  }
  #endif
}
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