import from UniRx and some modified.

Assets/UniRx.Async/Triggers/AsyncCollisionTrigger.cs

@@ -0,0 +1,69 @@
+
+#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.Collections.Generic;
+using System.Threading;
+using UnityEngine;
+using UnityEngine.EventSystems;
+
+namespace UniRx.Async.Triggers
+{
+    [DisallowMultipleComponent]
+    public class AsyncCollisionTrigger : AsyncTriggerBase
+    {
+        AsyncTriggerPromise<Collision> onCollisionEnter;
+        AsyncTriggerPromiseDictionary<Collision> onCollisionEnters;
+        AsyncTriggerPromise<Collision> onCollisionExit;
+        AsyncTriggerPromiseDictionary<Collision> onCollisionExits;
+        AsyncTriggerPromise<Collision> onCollisionStay;
+        AsyncTriggerPromiseDictionary<Collision> onCollisionStays;
+
+
+        protected override IEnumerable<ICancelablePromise> GetPromises()
+        {
+            return Concat(onCollisionEnter, onCollisionEnters, onCollisionExit, onCollisionExits, onCollisionStay, onCollisionStays);
+        }
+
+
+        void OnCollisionEnter(Collision collision)
+        {
+            TrySetResult(onCollisionEnter, onCollisionEnters, collision);
+        }
+
+
+        public UniTask OnCollisionEnterAsync(CancellationToken cancellationToken = default(CancellationToken))
+        {
+            return GetOrAddPromise(ref onCollisionEnter, ref onCollisionEnters, cancellationToken);
+        }
+
+
+        void OnCollisionExit(Collision collisionInfo)
+        {
+            TrySetResult(onCollisionExit, onCollisionExits, collisionInfo);
+        }
+
+
+        public UniTask OnCollisionExitAsync(CancellationToken cancellationToken = default(CancellationToken))
+        {
+            return GetOrAddPromise(ref onCollisionExit, ref onCollisionExits, cancellationToken);
+        }
+
+
+        void OnCollisionStay(Collision collisionInfo)
+        {
+            TrySetResult(onCollisionStay, onCollisionStays, collisionInfo);
+        }
+
+
+        public UniTask OnCollisionStayAsync(CancellationToken cancellationToken = default(CancellationToken))
+        {
+            return GetOrAddPromise(ref onCollisionStay, ref onCollisionStays, cancellationToken);
+        }
+
+
+    }
+}
+
+#endif
+