Hello, I have a JSON string and I need to add a field to it. Here was my first approach:

auto doc = from_json(jsonStr);
document builder{ doc.release() };
builder.append(kvp("$currentDate", make_document(kvp("lastModified", true))));

But I realize that a builder cannot be initialized from a document::value in any way. So my question is how can I:

• Parse a JSON string
• Append a new field
• Get the resulting document::value