从文件中读取一行后如何获取当前文件位置？

file = open("filename.txt", "r")
line = file.readline()
current_position = file.tell()
file.close()

try {
    BufferedReader reader = new BufferedReader(new FileReader("filename.txt"));
    String line = reader.readLine();
    long current_position = reader.getFilePointer();
    reader.close();
} catch (IOException e) {
    e.printStackTrace();
}

#include <iostream>
#include <fstream>
using namespace std;

int main() {
    ifstream file("filename.txt");
    string line;
    getline(file, line);
    streampos current_position = file.tellg();
    file.close();
    return 0;
}