C++中Lambada表达式种隐式捕获this指针的隐患问题

1#include <iostream>
2#include <functional>
3using namespace std;
4class Dispatcher
5{
6private:
7    std::function<void()> callback_;
8public:
9    void addRequest(std::function<void()> callback)
10    {
11        callback_ = callback;
12    }
13    void start()
14    {
15        callback_();
16    }
17};
18
19class Worker
20{
21public:
22    void start(Dispatcher* dispatcher)
23    {
24        dispatcher->addRequest([=](){notifier();});
25    }
26private:
27    void notifier()
28    {
29        bDone = true;
30    }
31    bool bDone{false};
32};
33
34int main()
35{
36    Dispatcher* dispatcher = new Dispatcher();
37    Worker* worker = new Worker();
38    worker->start(dispatcher);
39    delete worker;//open this line to get a crash
40    dispatcher->start();
41    return 0;
42}

如上代码所示：

1. 虽然这行代码：dispatcher->addRequest([=](){notifier();});中使用了[=]这样的隐式值捕获，但是notifier这里其实还是引用到了this->notifier这样的。所以是隐式的引用到了this指针。
2. delete worker以后this指针失效。
3. dispatcher回调worker以后，走到worker的notifer中，操作成员数据bDone。
4. 因为worker已经析构，crash。