message: Remove unused return values
diff: @@ -40,9 +40,8 @@ struct test_consumer {
  return *this;
  }
  - test_consumer& end_map() {
  + void end_map() {
  log.emplace_back("}");
  - return *this;
  }
  test_consumer& begin_list() {
  @@ -50,9 +49,8 @@ struct test_consumer {
  return *this;
  }
  - test_consumer& end_list() {
  + void end_list() {
  log.emplace_back("]");
  - return *this;
  }
  void key(std::string name) {
  @@ -70,8 +68,6 @@ struct test_consumer {
  }
  };
  -
  -
  struct ini_consumer {
  using inner_map = std::map<std::string, config_value>;
  using section_map = std::map<std::string, inner_map>;
  