三国卡牌客户端基础资源仓库
hch
4 天以前 cdac25a8e4f91a4663bf5f80994538dd263b757c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
using Cysharp.Threading.Tasks.Internal;
using System;
using System.Threading;
 
namespace Cysharp.Threading.Tasks.Linq
{
    public static partial class UniTaskAsyncEnumerable
    {
        public static UniTask<TSource> ElementAtAsync<TSource>(this IUniTaskAsyncEnumerable<TSource> source, int index, CancellationToken cancellationToken = default)
        {
            Error.ThrowArgumentNullException(source, nameof(source));
 
            return ElementAt.ElementAtAsync(source, index, cancellationToken, false);
        }
 
        public static UniTask<TSource> ElementAtOrDefaultAsync<TSource>(this IUniTaskAsyncEnumerable<TSource> source, int index, CancellationToken cancellationToken = default)
        {
            Error.ThrowArgumentNullException(source, nameof(source));
 
            return ElementAt.ElementAtAsync(source, index, cancellationToken, true);
        }
    }
 
    internal static class ElementAt
    {
        public static async UniTask<TSource> ElementAtAsync<TSource>(IUniTaskAsyncEnumerable<TSource> source, int index, CancellationToken cancellationToken, bool defaultIfEmpty)
        {
            var e = source.GetAsyncEnumerator(cancellationToken);
            try
            {
                int i = 0;
                while (await e.MoveNextAsync())
                {
                    if (i++ == index)
                    {
                        return e.Current;
                    }
                }
 
                if (defaultIfEmpty)
                {
                    return default;
                }
                else
                {
                    throw Error.ArgumentOutOfRange(nameof(index));
                }
            }
            finally
            {
                if (e != null)
                {
                    await e.DisposeAsync();
                }
            }
        }
    }
}