Making variance annotations optional based on build flavor.

Ix.NET/Source/System.Interactive.Async.Providers/IAsyncQueryable.cs

@@ -29,7 +29,11 @@ namespace System.Linq
     /// Asynchronous enumerable sequence represented by an expression tree.
     /// </summary>
     /// <typeparam name="T">The type of the elements in the sequence.</typeparam>
-    public interface IAsyncQueryable<out T> : IAsyncEnumerable<T>, IAsyncQueryable
+    public interface IAsyncQueryable<
+#if !NO_VARIANCE
+out
+#endif
+        T> : IAsyncEnumerable<T>, IAsyncQueryable
     {
     }
 }

Ix.NET/Source/System.Interactive.Async.Providers/IOrderedAsyncQueryable.cs

@@ -12,7 +12,11 @@ namespace System.Linq
     /// Ordered asynchronous enumerable sequence represented by an expression tree.
     /// </summary>
     /// <typeparam name="T">The type of the elements in the sequence.</typeparam>
-    public interface IOrderedAsyncQueryable<out T> : IAsyncQueryable<T>
+    public interface IOrderedAsyncQueryable<
+#if !NO_VARIANCE
+out
+#endif
+        T> : IAsyncQueryable<T>
     {
     }
 }