setjmp用法

#pragma once

#include <iostream>
#include <csetjmp>

using namespace std;

class rain_bow{
public:
	rain_bow() { cout << " rain_bow()" << endl;}
	~rain_bow() { cout <<"~rain_bow()" << endl;}
};

jmp_buf kansas;
int value = 0;

void oz1(){
	
	rain_bow rb;
	value = 2;
	for(int i = 0; i < 3; ++i){
		cout << " there is no place link home"<<std::endl;
	}
	longjmp(kansas, 47);
	
}

void oz2(){
	longjmp(kansas, 1);
}

void test_jmp(){

	if(setjmp(kansas)==0){

		value = 1;
		cout<<"[==> if]"<<endl;
		cout<<"1. setjmp -  value: " << value << endl;

		cout<<"tornado, witch, munchkins..."<<endl;

		oz1();//return back to the postion before setjmp(kansas)==0

	}else{

		//will come here after executoing oz()
		cout <<"[==> else 1]" <<endl;

		cout<<"2. longjmp - value : " << value << endl;

		cout<<" Auntie Em! "
			<< "I had the strangest dream..."
			<< endl;

	}

}


/*output:

[==> if]
1. setjmp -  value: 1
tornado, witch, munchkins...
rain_bow()
there is no place link home
there is no place link home
there is no place link home
~rain_bow()

2. longjmp - value : 2
[==> else] Auntie Em! I had the strangest dream...
请按任意键继续. . .


*/