Что-то не так со считыванием

ifstream fin;
    fin.open (path, ios_base :: binary | ios_base :: app | ios_base :: in);
    if(!fin.is_open())
    {
        cerr << "File couldn't be opened for reading!" << endl;
        exit (CANT_OPENED);
    } 
 
    // Allocation dynamic memory
    u8 *data;
    fin.seekg(0, ios::end);
    u64 length = fin.tellg();
    fin.seekg(0, ios::beg);
    data = new u8 [length];
    size_t i = 0;
 
    // Reading from a file to an array 
    while (!fin.eof())
    {
        fin >> data[i++];
    }
    
    cout << (int) data[length-2]<<endl;
    cout << (int) data[length-3]<<endl;
    cout << (int) data[length-4]<<endl;
    cout << "Checkpoint" << endl;
    fin.close();

    FILE* fin;
    const char* c = path.c_str();
    fin = fopen (c, "rb");
    if(fin == NULL)
    {
        cerr << "File couldn't be opened for reading!" << endl;
        exit (CANT_OPENED);
    } 
 
    // Allocation dynamic memory
    fseek(fin, 0, SEEK_END);
    size_t length = ftell(fin);
    fseek(fin, 0, SEEK_SET);
    u8 *data = new u8 [length];
    size_t i = 0;
    for (; i < length; i++)
        data[i] = getc(fin);
    
    /*while (!fin.eof())
    {
        fin >> data[i++];
    }*/
    // Reading from a file to an array 
    cout << (int) data[length-2]<<endl;
    cout << (int) data[length-3]<<endl;
    cout << (int) data[length-4]<<endl;
    cout << "Checkpoint" << endl;
    fclose(fin);

    std::ifstream file("путькфайлу",std::ios::binary);
    if(file.is_open())
    {
        std::vector content((std::istreambuf_iterator<char>(file)),{});
                 ...
    }

std::vector content((std::istreambuf_iterator<char>(file)),{})

vector <uint8_t> content((std::istreambuf_iterator<char>(fin)), {});

std::string s = (std::stringstream() << std::ifstream(path).rdbuf()).str();

ifstream fin (path, ifstream :: binary || ifstream ::  in);

ifstream fin (path, ios :: binary | ios ::  in);
    if(!fin.is_open())
    {
        cerr << "File couldn't be opened for reading!" << endl;
        exit (CANT_OPENED);
    }
    
    // Allocation dynamic memory
    fin.seekg(0, ios::end);
    u64 length = fin.tellg();
    fin.seekg(0, ios::beg);
    size_t i = 0;
    u8* data = new u8 [length];
    while (!fin.eof())
    {
        fin >> data[i++];
    }

    std::vector<uint8_t> content;
    std::ifstream file("путькфайлу",std::ios::binary);
    if(file.is_open())
    {
        file.seekg(0, std::ios::end);
        const auto length = file.tellg();
        file.seekg(0, std::ios::beg);
        content.resize(length);
        file.read((char*)content.data(), content.size());
    }

ifstream fin (path, ios :: binary | ios ::  in | ios :: app);
    if(!fin.is_open())
    {
        cerr << "File couldn't be opened for reading!" << endl;
        exit (CANT_OPENED);
    }
    size_t length;
    std::vector<uint8_t> content;
    std::ifstream file(path, std::ios::binary);
    if (file.is_open())
    {
        file.seekg(0, std::ios::end);
        length = file.tellg();
        file.seekg(0, std::ios::beg);
        content.resize(length);
        file.read((char*)content.data(), content.size());
    }
    
 
    cout << (int) content[length - 1]<<endl;
    cout << (int)content[length - 2]<<endl;
    cout << (int)content[length - 3]<<endl;
 
    cout << "Checkpoint" << endl;

ifstream fin (path, ios :: binary | ios ::  in | ios :: app);
    if(!fin.is_open())
    {
        cerr << "File couldn't be opened for reading!" << endl;
        exit (CANT_OPENED);
    }
    size_t length;
    u8* data;
    std::ifstream file(path, std::ios::binary);
    file.seekg(0, std::ios::end);
    length = file.tellg();
    file.seekg(0, std::ios::beg);
    data = new u8[length];
    if (file.is_open())
    {
        file.read((char*)data, length);
    }

...
        file.seekg(0, std::ios::end);
        const auto length = file.tellg();
        file.seekg(0, std::ios::beg);
        uint8_t* content=new uint8_t[length];
        file.read((char*)content, length);
 
        /*delete [] content;
        content=0;*/
...