C++マルチスレッドサブクラス「部分解析」の問題

#include 
#include 

using namespace std;

/*
* This is a simple example used to reveal memory issue when we destruct a object of child class.
*1.Set two break points as shown below.
*2.Watch the memory of "ch".
*3.Start the exmple.
* Observe the memory content of "ch", we can get the following conclusions:
* When we break at ~child(), the memory of "ch" is still valid.
* The moment we break at ~Base(), the "child" memory part of "ch" becomes invalid but still the "base" memory 
* part is valid.

* Knowing this feature is especially important when we program under muti-thread.
*/
class Base
{
public:
    Base()
    {
        name = "base object";
        cout << "Base()" << name << endl;
    }

    ~Base() 
    {
        // set a break point here.
        cout << "~Base() start " << name << endl;
    }
    string name;
};

class child :public Base
{
public:
    child()
    {
        cName = "child object";
        cout << "child()" << cName <// set a break point here.
        cout << "~child() start " << cName << endl;
    }
    string cName;
};

child *ch = new child();

int main()
{
    delete ch;
    return 0;
}