Use source generator to generate CountAsync overloads

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

@@ -11,7 +11,6 @@ namespace System.Linq
     partial class AsyncEnumerable
     {
 #if SUPPORT_FLAT_ASYNC_API
-        public static ValueTask<int> CountAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => CountAwaitAsyncCore<TSource>(source, predicate, cancellationToken);
         public static ValueTask<TSource> FirstAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => FirstAwaitAsyncCore<TSource>(source, predicate, cancellationToken);
         public static ValueTask<TSource?> FirstOrDefaultAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => FirstOrDefaultAwaitAsyncCore<TSource>(source, predicate, cancellationToken);
         public static Task ForEachAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, Task> action, CancellationToken cancellationToken = default) => ForEachAwaitAsyncCore<TSource>(source, action, cancellationToken);
@@ -96,7 +95,6 @@ namespace System.Linq
         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<int> CountAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => CountAwaitWithCancellationAsyncCore<TSource>(source, predicate, cancellationToken);
         public static ValueTask<TSource> FirstAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => FirstAwaitWithCancellationAsyncCore<TSource>(source, predicate, cancellationToken);
         public static ValueTask<TSource?> FirstOrDefaultAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => FirstOrDefaultAwaitWithCancellationAsyncCore<TSource>(source, predicate, cancellationToken);
         public static Task ForEachAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, Task> action, CancellationToken cancellationToken) => ForEachAwaitWithCancellationAsyncCore<TSource>(source, action, cancellationToken);
@@ -181,17 +179,6 @@ namespace System.Linq
         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>
-        /// Counts the elements in an async-enumerable sequence that satisfy a condition.
-        /// </summary>
-        /// <typeparam name="TSource">Type of elements in the source sequence.</typeparam>
-        /// <param name="source">A sequence of elements to count.</param>
-        /// <param name="predicate">An asynchronous predicate to apply to each element in the source sequence.</param>
-        /// <param name="cancellationToken">An optional cancellation token for cancelling the sequence at any time.</param>
-        /// <returns>A ValueTask containing the number of elements in the sequence that satisfy the predicate.</returns>
-        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="predicate"/> is <see langword="null"/>.</exception>
-        public static ValueTask<int> CountAwaitAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => CountAwaitAsyncCore<TSource>(source, predicate, cancellationToken);
-
         /// <summary>
         /// Returns the first element of an async-enumerable sequence that satisfies the condition in the predicate.
         /// </summary>
@@ -1139,7 +1126,6 @@ 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<int> CountAwaitWithCancellationAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => CountAwaitWithCancellationAsyncCore<TSource>(source, predicate, cancellationToken);
         public static ValueTask<TSource> FirstAwaitWithCancellationAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => FirstAwaitWithCancellationAsyncCore<TSource>(source, predicate, cancellationToken);
         public static ValueTask<TSource?> FirstOrDefaultAwaitWithCancellationAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default) => FirstOrDefaultAwaitWithCancellationAsyncCore<TSource>(source, predicate, cancellationToken);
         public static Task ForEachAwaitWithCancellationAsync<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, Task> action, CancellationToken cancellationToken) => ForEachAwaitWithCancellationAsyncCore<TSource>(source, action, cancellationToken);

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

@@ -88,7 +88,17 @@ namespace System.Linq
             }
         }
 
-        internal static ValueTask<int> CountAwaitAsyncCore<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate, CancellationToken cancellationToken = default)
+        /// <summary>
+        /// Counts the elements in an async-enumerable sequence that satisfy a condition.
+        /// </summary>
+        /// <typeparam name="TSource">Type of elements in the source sequence.</typeparam>
+        /// <param name="source">A sequence of elements to count.</param>
+        /// <param name="predicate">An asynchronous predicate to apply to each element in the source sequence.</param>
+        /// <param name="cancellationToken">An optional cancellation token for cancelling the sequence at any time.</param>
+        /// <returns>A ValueTask containing the number of elements in the sequence that satisfy the predicate.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="source"/> or <paramref name="predicate"/> is <see langword="null"/>.</exception>
+        [GenerateAsyncOverload]
+        private static ValueTask<int> CountAwaitAsyncCore<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, ValueTask<bool>> predicate, CancellationToken cancellationToken = default)
         {
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));
@@ -117,7 +127,8 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal static ValueTask<int> CountAwaitWithCancellationAsyncCore<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default)
+        [GenerateAsyncOverload]
+        private static ValueTask<int> CountAwaitWithCancellationAsyncCore<TSource>(this IAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, ValueTask<bool>> predicate, CancellationToken cancellationToken = default)
         {
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));