DotNext by Roman Sakno

<PackageReference Include="DotNext" Version="2.1.0" />

 Continuation

public static class Continuation
Represents various continuations.
using DotNext.Generic; using DotNext.Runtime; using System; using System.Runtime.CompilerServices; using System.Threading; using System.Threading.Tasks; namespace DotNext.Threading.Tasks { [System.Runtime.CompilerServices.NullableContext(1)] [System.Runtime.CompilerServices.Nullable(0)] public static class Continuation { private static Task<T> ContinueWithConstant<[System.Runtime.CompilerServices.Nullable(2)] T, [System.Runtime.CompilerServices.Nullable(0)] C>(Task<T> task, bool completedSynchronously, Func<Task<T>, T> continuation, CancellationToken token = default(CancellationToken), [System.Runtime.CompilerServices.Nullable(2)] TaskScheduler scheduler = null) where C : Constant<T>, new { if (!completedSynchronously) return task.ContinueWith(continuation, token, TaskContinuationOptions.ExecuteSynchronously, scheduler ?? TaskScheduler.Current); return CompletedTask<T, C>.Task; } public static Task<Task> OnCompleted(this Task task) { return task.ContinueWith(Func.Identity<Task>(), Intrinsics.DefaultOf<CancellationToken>(), TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Current); } public static Task<Task<R>> OnCompleted<[System.Runtime.CompilerServices.Nullable(2)] R>(this Task<R> task) { return task.ContinueWith(Func.Identity<Task<R>>(), Intrinsics.DefaultOf<CancellationToken>(), TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Current); } public static Task<T> OnFaulted<[System.Runtime.CompilerServices.Nullable(2)] T, [System.Runtime.CompilerServices.Nullable(0)] C>(this Task<T> task, [System.Runtime.CompilerServices.Nullable(2)] TaskScheduler scheduler = null) where C : Constant<T>, new { return ContinueWithConstant<T, C>(task, task.IsFaulted, Continuation<T, C>.WhenFaulted, Intrinsics.DefaultOf<CancellationToken>(), scheduler); } public static Task<T> OnFaultedOrCanceled<[System.Runtime.CompilerServices.Nullable(2)] T, [System.Runtime.CompilerServices.Nullable(0)] C>(this Task<T> task, [System.Runtime.CompilerServices.Nullable(2)] TaskScheduler scheduler = null) where C : Constant<T>, new { return ContinueWithConstant<T, C>(task, task.IsFaulted | task.IsCanceled, Continuation<T, C>.WhenFaultedOrCanceled, Intrinsics.DefaultOf<CancellationToken>(), scheduler); } public static Task<T> OnCanceled<[System.Runtime.CompilerServices.Nullable(2)] T, [System.Runtime.CompilerServices.Nullable(0)] C>(this Task<T> task, [System.Runtime.CompilerServices.Nullable(2)] TaskScheduler scheduler = null) where C : Constant<T>, new { return ContinueWithConstant<T, C>(task, task.IsCanceled, Continuation<T, C>.WhenCanceled, Intrinsics.DefaultOf<CancellationToken>(), scheduler); } } }