C++ primer 习题8.3

#include<iostream>#include<stdexcept>using namespace std;std::istream &get(std::istream &in){int ival;while(in >> ival,!in.eof()){if(in.bad())throw std::runtime_error("IO system corrupted");if(in.fail()){std::cerr << "bad data , try again \n";in.clear();in.ignore(200,' ');continue;}std::cout << ival << endl;}in.clear();return in;}int main(){double dval;get(cin);cin >> dval;cout << dval << endl;return 0;}