jsoncpp usage

jsoncpp_usage_test.cpp

int main(void) {
  std::string raw = "{\"test\": 1}";

  Json::Value root;// starts as "null"; will contain the root value after parsing
  Json::Reader reader;
  reader.parse(raw, root, false);
  int test_a = root["test"].asInt();

  DEBUG_TOKEN(test_a);
  // Get the value of the member of root named 'my-encoding', return 'UTF-32' if there is no
  // such member.
  std::string const my_encoding = root.get("my-encoding", "UTF-32").asString();

  // Get the value of the member of root named 'my-plug-ins'; return a 'null' value ib
  // there is no such member.
  const Json::Value my_plugins = root["my-plug-ins"];
  for (const auto &my_plugin : my_plugins)// Iterates over the sequence elements.
    std::string const temp_str = my_plugin.asString();

  int const a = root["my-indent"].get("length", 3).asInt();
  bool const b = root["my-indent"].get("use_space", true).asBool();

  // ...
  // At application shutdown to make the new configuration document:
  // Since Json::Value has implicit constructor for all value types, it is not
  // necessary to explicitly construct the Json::Value object:
  root["encoding"] = "utf8";
  root["indent"]["length"] = 10;
  root["indent"]["use_space"] = true;

  int test_int = root["indent"]["lngth"].asInt();

  std::cout << "test_int: " << test_int << "\n";

  // Make a new JSON document with the new configuration. Preserve original comments.
  std::cout << root << "\n";

  // For convenience, use `writeString()` with a specialized builder.
  Json::StreamWriterBuilder wbuilder;
  wbuilder["indentation"] = "";
  std::string const document = Json::FastWriter().write(root);
  std::cout << "res: " << document << "\n";

  return 0;
}