JeffreyZhao

/*
 * 引入voidable修饰符，用于修饰泛型参数。
 * 被修饰的泛型参数T，可以在代码里具体化为void类型。
 */

class Task<voidable T> { } // 带有voidable修饰

class List<T> { } // 不带voidable修饰

/*

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public class AsyncCompletion
{
    private static readonly TaskCompletionSource<Unit> CompletedSource;
 
    static AsyncCompletion()
    {
        CompletedSource = new TaskCompletionSource<Unit>();
        CompletedSource.SetResult(Unit.Default);
    }
    

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public class LimitConcurrencyLevelScheduler : LocalScheduler
{
  private readonly ActionBlock<Action> _actionBlock;

  public LimitConcurrencyLevelScheduler(int concurrencyLevel = 0, bool singleProducerConstrained = false)
  {
    var options = new ExecutionDataflowBlockOptions
    {
      MaxDegreeOfParallelism = concurrencyLevel <= 0 ? 1 : concurrencyLevel,
      SingleProducerConstrained = singleProducerConstrained

JeffreyZhao

// 其实这题可以写的很简单，它的关键根本不是CAS操作。

// 使用一个标志（flag也好，status判断也罢）来避免Start和Dispose重入是很容易
// 想到的手段，很多同学也这么做了。大部分同学遇到的问题是：假如StartCore已经
// 启动，那么如何让Dispose方法等待其完成。有些同学用while (true)，有些同学用
// 锁，但都避免不了让Dispose线程等待Start线程。

// 这里“避免等待”的关键在于要跳出思维界限：谁说DisposeCore方法一定要在Dispose
// 方法里执行的？我们就不能在Start里销毁对象吗？

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///////////////////////////////////////////////////////
// Talk is cheap. Show me the code. - Linus Torvalds
///////////////////////////////////////////////////////

public abstract class CalculatorBase : IDisposable {
    
    protected void StartCore() {
        // ...
    }
    

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struct MyKey {
    private readonly int _a;
    private readonly int _b;
    
    public MyKey(int a, int b) {
        _a = a;
        _b = b;
    }
}

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html, body {
    height: 100%;
}

.reeder-page {
    min-height: 100%;
    position: relative;
}

body {

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public static int Fac(int n, Func<int, int> cont) {
    if (n == 0) return cont(1);
    return Fac(n - 1, r => cont(n * r));
}

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public class MyClass<T>
{
    public class Nested { }
}

internal class Program
{
    private static void Main(string[] args)
    {
        Console.WriteLine(typeof(MyClass<>).GetNestedType("Nested")); // MyClass<>.Nested

JeffreyZhao

// As we all know, the generic List<T> class in .NET doesn't 
// have a RemoveMultiple method. Could you implement it for me?
// Say the elements are kept in the _items field, which is an
// array of type T. Also, use _count to keep the current number
// of elements.
// PS: You can compare two items with "==" operator.

namespace System.Collections.Generic
{
    public class List<T>