File->open(FileName, std::ios::out | std::ios::binary | std::ios::app);

    using closerWriteFile = std::function<void(std::ofstream*)>;
    using uptr_ofstream = std::unique_ptr<std::ofstream, closerWriteFile>;

uptr_ofstream OpenBinFileForWrite(cstring& FileName)
{
    closerWriteFile&& Closer = std::bind(CloseFileForWrite, _1, FileName, true);
    uptr_ofstream File(new std::ofstream, std::move(Closer));

    File->open(FileName, std::ios::out | std::ios::binary | std::ios::trunc); //ТЕПЕРЬ ПРИ ОТКРЫТИИ ОЧИЩАЕМ ФАЙЛ КЛИЕНТА
    return std::move(File);
}

void CloseFileForWrite(std::ofstream* File)
{
    File->close();
}

class OpenFiles
    {
        std::map<string, uptr_ofstream> Files;
        std::map<string, uint32> Monthes;

        mutable std::mutex MutexFiles;

    public:

        uptr_ofstream&& Get(cstring& FileName, cuint32 CurrentMonth)
        {
            std::lock_guard<std::mutex> Guard(MutexFiles);

            //remember working with data
            Monthes[FileName] = CurrentMonth;

            //initial find file in map
            std::map<string, uptr_ofstream>::iterator it;
            it = Files.find(FileName);
            if(it != Files.end()) return std::move(it->second);

            //add to map
            Files[FileName] = OpenBinFileForWrite(FileName);

            return std::move(Files[FileName]);
        }

        void CloseOldFiles(cuint32 CurrentMonth)
        {
            if(CurrentMonth != Consistency.GetOldestMonth()) return;

            std::lock_guard<std::mutex> Guard(MutexFiles);

            std::map<string, uptr_ofstream>::const_iterator it;

            for(const auto& Value: Monthes)
            {
                if(Value.second >= CurrentMonth) continue;

                //find files
                it = Files.find(Value.first);
                if(it == Files.end()) continue;

                //delete this file from map
                Files.erase(it);
            }

        }

    } CurrentFiles;

void WriteDataForClient(const myLib::array<writeData>& ArrayOfClient,
                                   const uint32 CurrentMonth,
                                   const string& Client)
{
    const string FileName = Settings.at("SubDirectoryWithOutputFiles") + Client + ".bin";

    //find file
    uptr_ofstream&& File = CurrentFiles.Get(FileName, CurrentMonth);

    //write file
    ArrayOfClient.WriteArrayToBinFile(std::move(File)); //ТУТ ДОБАВЛЯЮТСЯ ДАННЫЕ

    //flush added data
    File->flush();
}