在C++中读取文件时，如何使文件末尾有换行符？

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

int main() {
    std::ifstream file("example.txt");
    if (!file.is_open()) {
        std::cerr << "Failed to open file." << std::endl;
        return 1;
    }

    std::string line;
    while (std::getline(file, line)) {
        std::cout << line << std::endl; // 输出时会包含换行符
    }

    file.close();
    return 0;
}

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

int main() {
    std::ifstream file("example.txt", std::ios::in | std::ios::binary);
    if (!file.is_open()) {
        std::cerr << "Failed to open file." << std::endl;
        return 1;
    }

    std::string content((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
    std::cout << content; // 输出时会包含换行符

    file.close();
    return 0;
}

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

int main() {
    std::ifstream file("example.txt");
    if (!file.is_open()) {
        std::cerr << "Failed to open file." << std::endl;
        return 1;
    }

    std::string content;
    std::string line;
    while (std::getline(file, line)) {
        content += line + "\n";
    }

    // 检查并添加末尾的换行符
    if (!content.empty() && content.back() != '\n') {
        content += '\n';
    }

    std::cout << content; // 输出时会包含换行符

    file.close();
    return 0;
}