C++ fstream函数读取一行而不提取？

#include<iostream>
#include <fstream>
#include<string>

int main() {
    std::ifstream file("example.txt");
    std::string line;

    if (file.is_open()) {
        while (std::getline(file, line)) {
            std::cout<< line<< std::endl;
        }
        file.close();
    } else {
        std::cout << "Unable to open file"<< std::endl;
    }

    return 0;
}