Return, Bind, Map and Tap for async tasks

MonadicTaskExtensions.cs

    static class TaskExtensions
    {
        static Task<T> Return<T>(T task) => Task.FromResult(task);

        static async Task<R> Bind<T, R>(this Task<T> task, Func<T, Task<R>> cont) =>
            await cont(await task.ConfigureAwait(false)).ConfigureAwait(false);

        static async Task<R> Map<T, R>(this Task<T> task, Func<T, R> map) =>
            map(await task.ConfigureAwait(false));

        static async Task<T> Tap<T>(this Task<T> task, Func<T, Task> action)
        {
            await action(await task);
            return await task;
        }
    }