#include <iostream>

#include <string>

#include <fstream>

#include <exception>

class FileHandle{

private:

std::ofstream filestream;

std::string filename;

public:

FileHandle(const std::string& name) : filename(name){

filestream.open(filename);

if(!filestream.is_open()){

throw std::runtime_error("Could not open file: "+filename);

}

std::cout<<"[RAII] File "<<filename<<" opened.\n";

}

FileHandle(FileHandle&& other)noexcept :

filestream(std::move(other.filestream)),

filename(std::move(other.filename)){

std::cout<<"[RAII] Moved ownership from "<<filename<<"\n";

}

~FileHandle(){

if(filestream.is_open()){

filestream.close();

std::cout<<"[RAII] File "<<filename<<" closed automatically.\n";

}

}

void write(const std::string& text){

filestream<<text<<std::endl;

}

FileHandle(const FileHandle&) = delete;

FileHandle& operator=(const FileHandle&) = delete;

};

void processFile(){

FileHandle myFile("test.txt");

myFile.write("Hello RAII....");

std::cout<<"Simulating an error...\n";

throw std::runtime_error("Something went wrong! In process.");

myFile.write("This will never be written");

}

int main(){

try{

processFile();

}catch(const std::exception& e){

std::cout<< "Caught exception: " << e.what() << "\n";

}

std::cout<<"Program continues safely.\n";

return 0;

}