import from UniRx and some modified.

Assets/UniRx.Async/CancellationTokenSourceExtensions.cs

@@ -0,0 +1,48 @@
+#if CSHARP_7_OR_LATER || (UNITY_2018_3_OR_NEWER && (NET_STANDARD_2_0 || NET_4_6))
+#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
+
+using System.Threading;
+using UnityEngine;
+using UniRx.Async.Triggers;
+using System;
+
+namespace UniRx.Async
+{
+    public static class CancellationTokenSourceExtensions
+    {
+        public static void CancelAfterSlim(this CancellationTokenSource cts, int millisecondsDelay, bool ignoreTimeScale = false, PlayerLoopTiming delayTiming = PlayerLoopTiming.Update)
+        {
+            var delay = UniTask.Delay(millisecondsDelay, ignoreTimeScale, delayTiming, cts.Token);
+            CancelAfterCore(cts, delay).Forget();
+        }
+
+        public static void CancelAfterSlim(this CancellationTokenSource cts, TimeSpan delayTimeSpan, bool ignoreTimeScale = false, PlayerLoopTiming delayTiming = PlayerLoopTiming.Update)
+        {
+            var delay = UniTask.Delay(delayTimeSpan, ignoreTimeScale, delayTiming, cts.Token);
+            CancelAfterCore(cts, delay).Forget();
+        }
+
+        static async UniTaskVoid CancelAfterCore(CancellationTokenSource cts, UniTask delayTask)
+        {
+            var alreadyCanceled = await delayTask.SuppressCancellationThrow();
+            if (!alreadyCanceled)
+            {
+                cts.Cancel();
+                cts.Dispose();
+            }
+        }
+
+        public static void RegisterRaiseCancelOnDestroy(this CancellationTokenSource cts, Component component)
+        {
+            RegisterRaiseCancelOnDestroy(cts, component.gameObject);
+        }
+
+        public static void RegisterRaiseCancelOnDestroy(this CancellationTokenSource cts, GameObject gameObject)
+        {
+            var trigger = gameObject.GetAsyncDestroyTrigger();
+            trigger.AddCancellationTriggerOnDestory(cts);
+        }
+    }
+}
+
+#endif