从c++primer6中抄下来的代码 为什么提示那个 ppb错误

#include <iostream>
using namespace std;
struct antar{ int year; /* some really interesting dat,etc.*/};
int main(){ antar s01,s02,s03; s01.year=1998;
antar*pa=&s02; pa->year=1999;
antar trio[3]; trio[0].year=2003;
cout<<trio->year<<endl; const antar*arp[3]= { &s01,&s02,&s03 }; cout<<arp[1]->year<<endl;
const antar ** ppa = arp;
auto ppb = arp;
cout<<(*ppa)->year<<endl; cout<<(*(ppb+1))->year<<endl; return 0;
}