Use source generator to generate ToLookupAsync overloads

Ix.NET/Source/System.Linq.Async/System/Linq/AsyncEnumerable.AsyncOverloads.cs

@@ -11,82 +11,16 @@ namespace System.Linq
     partial class AsyncEnumerable
     {
 #if SUPPORT_FLAT_ASYNC_API
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey>(source, keySelector, cancellationToken);
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, cancellationToken);
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey>(source, keySelector, comparer, cancellationToken);
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, comparer, cancellationToken);
         public static IAsyncEnumerable<TSource> Where<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate) => WhereAwaitCore<TSource>(source, predicate);
         public static IAsyncEnumerable<TSource> Where<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, int, ValueTask<bool>> predicate) => WhereAwaitCore<TSource>(source, predicate);
         public static IAsyncEnumerable<TResult> Zip<TFirst, TSecond, TResult>(this IAsyncEnumerable<TFirst> first, IAsyncEnumerable<TSecond> second, Func<TFirst, TSecond, ValueTask<TResult>> selector) => ZipAwaitCore<TFirst, TSecond, TResult>(first, second, selector);
 
 #if !NO_DEEP_CANCELLATION
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(source, keySelector, cancellationToken);
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, cancellationToken);
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(source, keySelector, comparer, cancellationToken);
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, comparer, cancellationToken);
         public static IAsyncEnumerable<TSource> Where<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate) => WhereAwaitWithCancellationCore<TSource>(source, predicate);
         public static IAsyncEnumerable<TSource> Where<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, int, CancellationToken, ValueTask<bool>> predicate) => WhereAwaitWithCancellationCore<TSource>(source, predicate);
         public static IAsyncEnumerable<TResult> Zip<TFirst, TSecond, TResult>(this IAsyncEnumerable<TFirst> first, IAsyncEnumerable<TSecond> second, Func<TFirst, TSecond, CancellationToken, ValueTask<TResult>> selector) => ZipAwaitWithCancellationCore<TFirst, TSecond, TResult>(first, second, selector);
 #endif
 #else
-        /// <summary>
-        /// Creates a lookup from an async-enumerable sequence by invoking a key-selector function on each element and awaiting the result.
-        /// </summary>
-        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
-        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
-        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
-        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
-        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
-        /// <returns>A ValueTask containing a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
-        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> is null.</exception>
-        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey>(source, keySelector, cancellationToken);
-
-        /// <summary>
-        /// Creates a lookup from an async-enumerable sequence by invoking key and element selector functions on each source element and awaiting the results.
-        /// </summary>
-        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
-        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
-        /// <typeparam name="TElement">The type of the lookup value computed for each element in the source sequence.</typeparam>
-        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
-        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
-        /// <param name="elementSelector">An asynchronous transform function to produce a result element value from each element.</param>
-        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
-        /// <returns>An async-enumerable sequence containing a single element with a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
-        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> or <paramref name="elementSelector"/> is null.</exception>
-        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, cancellationToken);
-
-        /// <summary>
-        /// Creates a lookup from an async-enumerable sequence by invoking a key-selector function on each element and awaiting the result.
-        /// </summary>
-        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
-        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
-        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
-        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
-        /// <param name="comparer">An equality comparer to compare keys.</param>
-        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
-        /// <returns>A ValueTask containing a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
-        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> or <paramref name="comparer"/> is null.</exception>
-        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey>(source, keySelector, comparer, cancellationToken);
-
-        /// <summary>
-        /// Creates a lookup from an async-enumerable sequence by invoking key and element selector functions on each source element and awaiting the results.
-        /// </summary>
-        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
-        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
-        /// <typeparam name="TElement">The type of the lookup value computed for each element in the source sequence.</typeparam>
-        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
-        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
-        /// <param name="elementSelector">An asynchronous transform function to produce a result element value from each source element.</param>
-        /// <param name="comparer">An equality comparer to compare keys.</param>
-        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
-        /// <returns>A ValueTask containing a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
-        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> or <paramref name="elementSelector"/> or <paramref name="comparer"/> is null.</exception>
-        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, comparer, cancellationToken);
-
         /// <summary>
         /// Filters the elements of an async-enumerable sequence based on an asynchronous predicate.
         /// </summary>
@@ -121,10 +55,6 @@ namespace System.Linq
         public static IAsyncEnumerable<TResult> ZipAwait<TFirst, TSecond, TResult>(this IAsyncEnumerable<TFirst> first, IAsyncEnumerable<TSecond> second, Func<TFirst, TSecond, ValueTask<TResult>> selector) => ZipAwaitCore<TFirst, TSecond, TResult>(first, second, selector);
 
 #if !NO_DEEP_CANCELLATION
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitWithCancellationAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(source, keySelector, cancellationToken);
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitWithCancellationAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, cancellationToken);
-        public static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitWithCancellationAsync<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(source, keySelector, comparer, cancellationToken);
-        public static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitWithCancellationAsync<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey> comparer, CancellationToken cancellationToken = default) => ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, comparer, cancellationToken);
         public static IAsyncEnumerable<TSource> WhereAwaitWithCancellation<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate) => WhereAwaitWithCancellationCore<TSource>(source, predicate);
         public static IAsyncEnumerable<TSource> WhereAwaitWithCancellation<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, int, CancellationToken, ValueTask<bool>> predicate) => WhereAwaitWithCancellationCore<TSource>(source, predicate);
         public static IAsyncEnumerable<TResult> ZipAwaitWithCancellation<TFirst, TSecond, TResult>(this IAsyncEnumerable<TFirst> first, IAsyncEnumerable<TSecond> second, Func<TFirst, TSecond, CancellationToken, ValueTask<TResult>> selector) => ZipAwaitWithCancellationCore<TFirst, TSecond, TResult>(first, second, selector);

Ix.NET/Source/System.Linq.Async/System/Linq/Operators/ToLookup.cs

@@ -51,10 +51,35 @@ namespace System.Linq
             }
         }
 
-        internal static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) =>
+        /// <summary>
+        /// Creates a lookup from an async-enumerable sequence by invoking a key-selector function on each element and awaiting the result.
+        /// </summary>
+        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
+        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
+        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
+        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
+        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
+        /// <returns>A ValueTask containing a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> is null.</exception>
+        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) =>
             ToLookupAwaitAsyncCore<TSource, TKey>(source, keySelector, comparer:null, cancellationToken);
 
-        internal static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
+        /// <summary>
+        /// Creates a lookup from an async-enumerable sequence by invoking a key-selector function on each element and awaiting the result.
+        /// </summary>
+        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
+        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
+        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
+        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
+        /// <param name="comparer">An equality comparer to compare keys.</param>
+        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
+        /// <returns>A ValueTask containing a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> or <paramref name="comparer"/> is null.</exception>
+        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
         {
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));
@@ -70,10 +95,12 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) =>
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, CancellationToken cancellationToken = default) =>
             ToLookupAwaitWithCancellationAsyncCore(source, keySelector, comparer: null, cancellationToken);
 
-        internal static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TSource>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
         {
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));
@@ -136,10 +163,39 @@ namespace System.Linq
             }
         }
 
-        internal static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) =>
+        /// <summary>
+        /// Creates a lookup from an async-enumerable sequence by invoking key and element selector functions on each source element and awaiting the results.
+        /// </summary>
+        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
+        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
+        /// <typeparam name="TElement">The type of the lookup value computed for each element in the source sequence.</typeparam>
+        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
+        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
+        /// <param name="elementSelector">An asynchronous transform function to produce a result element value from each element.</param>
+        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
+        /// <returns>An async-enumerable sequence containing a single element with a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> or <paramref name="elementSelector"/> is null.</exception>
+        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) =>
             ToLookupAwaitAsyncCore<TSource, TKey, TElement>(source, keySelector, elementSelector, comparer: null, cancellationToken);
 
-        internal static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
+        /// <summary>
+        /// Creates a lookup from an async-enumerable sequence by invoking key and element selector functions on each source element and awaiting the results.
+        /// </summary>
+        /// <typeparam name="TSource">The type of the elements in the source sequence.</typeparam>
+        /// <typeparam name="TKey">The type of the lookup key computed for each element in the source sequence.</typeparam>
+        /// <typeparam name="TElement">The type of the lookup value computed for each element in the source sequence.</typeparam>
+        /// <param name="source">An async-enumerable sequence to create a lookup for.</param>
+        /// <param name="keySelector">An asynchronous function to extract a key from each element.</param>
+        /// <param name="elementSelector">An asynchronous transform function to produce a result element value from each source element.</param>
+        /// <param name="comparer">An equality comparer to compare keys.</param>
+        /// <param name="cancellationToken">The optional cancellation token to be used for cancelling the sequence at any time.</param>
+        /// <returns>A ValueTask containing a lookup mapping unique key values onto the corresponding source sequence's elements.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="keySelector"/> or <paramref name="elementSelector"/> or <paramref name="comparer"/> is null.</exception>
+        /// <remarks>The return type of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.</remarks>
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<TKey>> keySelector, Func<TSource, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
         {
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));
@@ -157,10 +213,12 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) =>
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, CancellationToken cancellationToken = default) =>
             ToLookupAwaitWithCancellationAsyncCore(source, keySelector, elementSelector, comparer: null, cancellationToken);
 
-        internal static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
+        [GenerateAsyncOverload]
+        private static ValueTask<ILookup<TKey, TElement>> ToLookupAwaitWithCancellationAsyncCore<TSource, TKey, TElement>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<TKey>> keySelector, Func<TSource, CancellationToken, ValueTask<TElement>> elementSelector, IEqualityComparer<TKey>? comparer, CancellationToken cancellationToken = default)
         {
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));