add UniTask.AsValueTask for Unity

src/UniTask/Assets/Plugins/UniTask/Runtime/IUniTaskSource.cs

@@ -19,7 +19,7 @@ namespace Cysharp.Threading.Tasks
 
     // similar as IValueTaskSource
     public interface IUniTaskSource
-#if !UNITY_2018_3_OR_NEWER && !NETSTANDARD2_0
+#if !NETSTANDARD2_0
         : System.Threading.Tasks.Sources.IValueTaskSource
 #pragma warning disable CS0108
 #endif
@@ -30,7 +30,7 @@ namespace Cysharp.Threading.Tasks
 
         UniTaskStatus UnsafeGetStatus(); // only for debug use.
 
-#if !UNITY_2018_3_OR_NEWER && !NETSTANDARD2_0
+#if !NETSTANDARD2_0
 #pragma warning restore CS0108
 
         System.Threading.Tasks.Sources.ValueTaskSourceStatus System.Threading.Tasks.Sources.IValueTaskSource.GetStatus(short token)
@@ -53,13 +53,13 @@ namespace Cysharp.Threading.Tasks
     }
 
     public interface IUniTaskSource<out T> : IUniTaskSource
-#if !UNITY_2018_3_OR_NEWER && !NETSTANDARD2_0
+#if !NETSTANDARD2_0
         , System.Threading.Tasks.Sources.IValueTaskSource<T>
 #endif
     {
         new T GetResult(short token);
 
-#if !UNITY_2018_3_OR_NEWER && !NETSTANDARD2_0
+#if !NETSTANDARD2_0
 
         new public UniTaskStatus GetStatus(short token)
         {

src/UniTask/Assets/Plugins/UniTask/Runtime/UniTask.AsValueTask.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: d38f0478933be42d895c37b862540a1c
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

src/UniTask/Assets/Plugins/UniTask/Runtime/UniTask.cs

@@ -69,8 +69,6 @@ namespace Cysharp.Threading.Tasks
             return new UniTask<bool>(new IsCanceledSource(source), token);
         }
 
-#if !UNITY_2018_3_OR_NEWER
-
         public static implicit operator System.Threading.Tasks.ValueTask(in UniTask self)
         {
             if (self.source == null)
@@ -85,8 +83,6 @@ namespace Cysharp.Threading.Tasks
 #endif
         }
 
-#endif
-
         public override string ToString()
         {
             if (source == null) return "()";
@@ -440,8 +436,6 @@ namespace Cysharp.Threading.Tasks
             return self.AsUniTask();
         }
 
-#if !UNITY_2018_3_OR_NEWER
-
         public static implicit operator System.Threading.Tasks.ValueTask<T>(in UniTask<T> self)
         {
             if (self.source == null)
@@ -456,8 +450,6 @@ namespace Cysharp.Threading.Tasks
 #endif
         }
 
-#endif
-
         /// <summary>
         /// returns (bool IsCanceled, T Result) instead of throws OperationCanceledException.
         /// </summary>