138.安全退出的异常,要用throw 尽量不用exit(0)

#include<iostream>

#include<cstdlib>
using namespace std;
////非安全退出，结束进程,
//C++ 必须释放对象，最后结束，安全退出

class pstr
{
    int *p;
public:
    pstr()
    {
        cout << "构造" << endl;
        p = new int[1024 * 1024];
    }
    ~pstr()
    {
        cout << "析构" << endl;

        delete[] p;

    }
};
void run3(int i)
{
    if (i == 0)
    {
        //throw  1;
        exit(0);  //非安全退出，结束进程
        //安全退出，释放对象内存，再结束进程
    } 
    else
    {
        cout << "run3" << endl;
    }
    
}
void run2(int i)
{
    pstr p2;
    run3(0);
}

void run1(int i)
{
    pstr p1;
    run2(i);
}

void main()
{
    try
    {
        run1(0);
    }
    catch (int i)
    {
        cout << i << "error";

    }

    std::cin.get();
    exit(0);
}