UniTaskCancellationTokenExtensions.cs

#if CSHARP_7_OR_LATER || (UNITY_2018_3_OR_NEWER && (NET_STANDARD_2_0 || NET_4_6))
#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member

using System.Threading;
using UniRx.Async;

namespace UniRx
{
    public static class UniTaskCancellationTokenExtensions
    {
        private static readonly CancellationToken cancelledToken = new CancellationToken(true);

        public static CancellationToken ToCancellationToken<T>(this UniTask<T> task)
        {
            if (task.IsCompleted)
            {
                return cancelledToken;
            }

            var source = new CancellationTokenSource();
            Fire(source, task).Forget();
            return source.Token;
        }

        public static CancellationToken ToCancellationToken(this UniTask task)
        {
            if (task.IsCompleted)
            {
                return cancelledToken;
            }

            var source = new CancellationTokenSource();
            Fire(source, task).Forget();
            return source.Token;
        }

        static async UniTaskVoid Fire<T>(CancellationTokenSource source, UniTask<T> task)
        {
            try
            {
                await task;
            }
            catch
            {
            }

            source.Cancel();
        }

        static async UniTaskVoid Fire(CancellationTokenSource source, UniTask task)
        {
            try
            {
                await task;
            }
            catch
            {
            }

            source.Cancel();
        }
    }
}

#endif