I have a problem with creating a simple array with values using vibe.data.json. Here's my code:

Json j = Json.emptyObject;
j.name = "Bert";
j.a = [1, 2, 3];
writefln("JSON: %s", j.toString());

When I launch it I get:

JSON: {"a":"<rubbish here>","name":"Bert"}

Rubbish is likely those 3 values (1,2,3) each represented as a character.

PS: Maybe I was not attentive reading the docs, but I didn't find any sample on how to do that. I'm using vibe.d 0.7.20.