Reordering GroupJoin overloads.

Ix.NET/Source/System.Interactive.Async/GroupJoin.cs

@@ -9,7 +9,7 @@ namespace System.Linq
 {
     public static partial class AsyncEnumerable
     {
-        public static IAsyncEnumerable<TResult> GroupJoin<TOuter, TInner, TKey, TResult>(this IAsyncEnumerable<TOuter> outer, IAsyncEnumerable<TInner> inner, Func<TOuter, TKey> outerKeySelector, Func<TInner, TKey> innerKeySelector, Func<TOuter, IAsyncEnumerable<TInner>, TResult> resultSelector, IEqualityComparer<TKey> comparer)
+        public static IAsyncEnumerable<TResult> GroupJoin<TOuter, TInner, TKey, TResult>(this IAsyncEnumerable<TOuter> outer, IAsyncEnumerable<TInner> inner, Func<TOuter, TKey> outerKeySelector, Func<TInner, TKey> innerKeySelector, Func<TOuter, IAsyncEnumerable<TInner>, TResult> resultSelector)
         {
             if (outer == null)
                 throw new ArgumentNullException(nameof(outer));
@@ -21,13 +21,11 @@ namespace System.Linq
                 throw new ArgumentNullException(nameof(innerKeySelector));
             if (resultSelector == null)
                 throw new ArgumentNullException(nameof(resultSelector));
-            if (comparer == null)
-                throw new ArgumentNullException(nameof(comparer));
 
-            return new GroupJoinAsyncEnumerable<TOuter, TInner, TKey, TResult>(outer, inner, outerKeySelector, innerKeySelector, resultSelector, comparer);
+            return outer.GroupJoin(inner, outerKeySelector, innerKeySelector, resultSelector, EqualityComparer<TKey>.Default);
         }
 
-        public static IAsyncEnumerable<TResult> GroupJoin<TOuter, TInner, TKey, TResult>(this IAsyncEnumerable<TOuter> outer, IAsyncEnumerable<TInner> inner, Func<TOuter, TKey> outerKeySelector, Func<TInner, TKey> innerKeySelector, Func<TOuter, IAsyncEnumerable<TInner>, TResult> resultSelector)
+        public static IAsyncEnumerable<TResult> GroupJoin<TOuter, TInner, TKey, TResult>(this IAsyncEnumerable<TOuter> outer, IAsyncEnumerable<TInner> inner, Func<TOuter, TKey> outerKeySelector, Func<TInner, TKey> innerKeySelector, Func<TOuter, IAsyncEnumerable<TInner>, TResult> resultSelector, IEqualityComparer<TKey> comparer)
         {
             if (outer == null)
                 throw new ArgumentNullException(nameof(outer));
@@ -39,8 +37,10 @@ namespace System.Linq
                 throw new ArgumentNullException(nameof(innerKeySelector));
             if (resultSelector == null)
                 throw new ArgumentNullException(nameof(resultSelector));
+            if (comparer == null)
+                throw new ArgumentNullException(nameof(comparer));
 
-            return outer.GroupJoin(inner, outerKeySelector, innerKeySelector, resultSelector, EqualityComparer<TKey>.Default);
+            return new GroupJoinAsyncEnumerable<TOuter, TInner, TKey, TResult>(outer, inner, outerKeySelector, innerKeySelector, resultSelector, comparer);
         }
 
         private sealed class GroupJoinAsyncEnumerable<TOuter, TInner, TKey, TResult> : IAsyncEnumerable<TResult>