请用C++写一个TCP/IP文件传输模板（指定ip和端口）

在C++中，实现一个基础的TCP/IP文件传输通常会涉及到`boost.asio`库，因为它提供了异步IO的支持，使得网络编程变得更加简单。以下是一个简单的模板，它使用了客户端模式，发送和接收文件内容：

#include <iostream>
#include <fstream>
#include <boost/asio.hpp>

using boost::asio::ip::tcp;

class FileTransferClient {
public:
    FileTransferClient(const std::string& server_ip, int server_port, const std::string& file_path)
        : io_service_(boost::asio::ip::tcp::v4()), socket_(io_service_), resolver_(io_service_)
    {
        start();
        open_file(file_path);
    }

private:
    void start() {
        tcp::resolver::query query(server_ip, std::to_string(server_port));
        resolver_.resolve(query, ec_);
        
        if (ec_) {
            std::cerr << "Failed to resolve host: " << ec_ << std::endl;
            return;
        }
        
        connect(socket_, resolver_.result(), ec_);
        
        if (ec_) {
            std::cerr << "Failed to connect: " << ec_ << std::endl;
            return;
        }
    }

    void open_file(const std::string& file_path) {
        ifstream file(file_path, std::ios::binary);
        if (!file.is_open()) {
            std::cerr << "Failed to open file: " << file_path << std::endl;
            return;
        }

        send_data("BEGIN_FILE\n", file);
    }

    template<typename T>
    void send_data(const char* data, T& source) {
        boost::array<char, 4096> buffer;
        while (source.read(buffer.data(), buffer.size())) {
            socket_.write_some(boost::asio::buffer(data, strlen(data)));
            socket_.write_some(buffer.data(), source.gcount());
        }
        if (source.gcount() > 0) {
            socket_.write_some(buffer.data(), source.gcount());
        }
        send_data("END_FILE\n", source); // Send end marker after sending all data
    }

    void close_connection() {
        boost::system::error_code ignored_error;
        socket_.shutdown(tcp::socket::shutdown_both, ignored_error);
    }

private:
    boost::asio::io_service& io_service_;
    tcp::socket socket_;
    tcp::resolver resolver_;
    boost::system::error_code ec_;
};

int main() {
    try {
        FileTransferClient client{"example.com", 8080, "path/to/file.txt"};
    } catch (std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }

    return 0;
}

注意：这个示例只是一个基本框架，并未包含错误处理、重试机制以及文件断点续传等功能。在实际应用中，你需要根据需要对其进行完善。