Method set_null

externals/picojson/picojson.h:974–977

  default_parse_context(value *out, size_t depths = DEFAULT_MAX_DEPTHS) : out_(out), depths_(depths) {
  }
  bool set_null() {
    *out_ = value();
    return true;
  }
  bool set_bool(bool b) {
    *out_ = value(b);
    return true;