C++ 读取文件内容到指定类型的变量

#include <iostream>#include <fstream>#include <sstream>#include <string>using namespace std;int main(){cout << "input the file name: ";string file_name;cin >> file_name;cout << endl;// ifstream infile("1.txt");ifstream infile(file_name.c_str());string line;while (std::getline(infile, line)){std::istringstream iss(line);int a, b;if (!(iss >> a >> b)) { break; } // errorcout << "a : " << a << endl;cout << "b : " << b << endl;}return 1;}