copy a JSONValue

[Alex via Digitalmars-d-learn]

Hi everybody,
I'm little at loss: as documented, a JSONValue is only shallow 
copied:

void main()
{
     import std.json;
     import std.stdio;

     string s = "{ \"language\": \"D\", \"rating\": 3.14, 
\"code\": 42 }";
     JSONValue j = parseJSON(s);
     writeln("code: ", j["code"].integer);

     auto j2 = j;
     j2["code"] = 43;
     writeln("code of j2: ", j2["code"].integer);
     writeln("code of j: ", j["code"].integer);
}

So the effect that the code of "j" is altered was expected.

The question is: how to make a deep copy of a JSONValue? Is there 
a simple way without copying the source string around? Or, would 
this be the simplest way?

Thanks in advance
Alex