Reading data from the network without knowing the size of the buffer that is coming

[Roman Sztergbaum]

Hello !

in my function :

```D
   private config_load_answer load_config(string[] args)
     in(args !is null, "args cannot be null")
     in(args.length == 2, "need 1 arguments")
     out(r; r.state == "SUCCESS", "load_config should succeed")
     out(r; !r.config_name.empty, "config_name should not be 
empty")
     out(r; r.config_id > 0, "config_id should be different than 
0")
     {
         string config_key;
         string readonly_config_key;
         getopt(args, "key", &config_key, "readonly_key", 
&readonly_config_key);
         auto cfg = 
deserialize_to!config_load("../API_doc/json_recipes/config_load.json");
         cfg.config_key = config_key;
         cfg.readonly_config_key = readonly_config_key;
         writeln(cfg);
         writeln(cfg.serializeToJsonPretty);
         client_.socket.send(cfg.serializeToJson);
         auto answer = new ubyte[256]; //
         client_.socket.receive(answer);
         (cast(string) answer).writeln;
         return (cast(string) 
answer).deserialize!config_load_answer;
     }
```

I would like to get rid of the "ubytes[256]" because I do not 
know the size of the data that is comming, I would like to read 
the entire buffer that I send at once. Can someone point me?

(i'm pretty new to D langage, but i'm familiar with C++, and for 
example in boost asio  we have `byte_transfered` so we can create 
a buffer with this size and read the incoming data)

Thank's a lot for your help !