// Select is necessary so bucket contents are streamed too
yield return resultSelector(bucket.Select(x => x));

有一条我不太明白的评论.我已经测试了这种方法而没有使用Select,它运行良好.但似乎有一些我遗漏的东西.我想不出任何必要的例子,那么在这里使用Select(x => x)的实际目的是什么？

以下是完整的源代码供参考：

private static IEnumerable<TResult> BatchImpl<TSource,TResult>(
        this IEnumerable<TSource> source,int size,Func<IEnumerable<TSource>,TResult> resultSelector)
    {
        TSource[] bucket = null;
        var count = 0;
 
        foreach (var item in source)
        {
            if (bucket == null)
                bucket = new TSource[size];
 
            bucket[count++] = item;
 
            // The bucket is fully buffered before it's yielded
            if (count != size)
                continue;
 
            // Select is necessary so bucket contents are streamed too
            yield return resultSelector(bucket.Select(x => x));
 
            bucket = null;
            count = 0;
        }
 
        // Return the last bucket with all remaining elements
        if (bucket != null && count > 0)
            yield return resultSelector(bucket.Take(count));
    }