Code:

class A
{
     public :
              class xReadFailed {};
              void create_image(const char * filename)
              {
                    fstream stream;
                    stream.open(filename, ios::in | ios::binary);

                    stream.seekg(0, ios::end);
                    long bytesize = stream.tellg();
                    stream.seekg(0, ios::beg);

                    imagedata = new char[bytesize];

                    stream.read(imagedata, bytesize);
                    if(!stream) throw xReadFailed();

                    stream.close();
             }
    private :
             char *imagedata;
};