Continuation without unecessary allocation via static method and cached delegate

Ignorer.cs

public static class TaskExtensions
{
  private static Action<Task> IgnorerContinuationAction = IgnorerContinuation;
  
  public static void Ignore(this Task task)
  {
      if (task.IsCompleted)
      {
          var exception = task.Exception;
      }
      else
      {
          task.ContinueWith(
              IgnorerContinuationAction,
              CancellationToken.None,
              TaskContinuationOptions.OnlyOnFaulted | TaskContinuationOptions.ExecuteSynchronously,
              TaskScheduler.Default);
      }
  }

  private static void IgnorerContinuation(Task task)
  {
      var exception = task.Exception;
  }
}

Created in response to this Twitter discussion: https://twitter.com/reubenbond/status/920402373624791040