Template Function cras::getParam(const ::ros::NodeHandle&, const ::std::string&, const ::cras::optional<ResultType>&, const ::std::string&, const ::cras::GetParamOptions<ResultType, ParamServerType>&)

Function Documentation

template<typename ResultType, typename ParamServerType = typename ::cras::DefaultParamServerType<ResultType>::type, ::cras::check_get_param_types<ResultType, ParamServerType>* = nullptr>
inline ResultType cras::getParam(const ::ros::NodeHandle &node, const ::std::string &name, const ::cras::optional<ResultType> &defaultValue = ResultType(), const ::std::string &unit = "", const ::cras::GetParamOptions<ResultType, ParamServerType> &options = {})

Get the value of the given ROS parameter, falling back to the specified default value (if not nullopt), and print out a ROS log message with the loaded values (if specified).

Template Parameters:

  • ResultType – Param type (the C++ type). It is converted from the intermediate ParamServerType using options.toResult function (which defaults to static_cast).

  • ParamServerType – Intermediate type to which the XmlRpcValue read from parameter server is converted. The conversion is done using options.toParam function (which defaults to cras::convert). Most overloads of cras::convert are in xmlrpc_value_utils.hpp, but you can add your own.

Parameters:

  • node – [in] The node handle from which parameters are read.

  • name – [in] Name of the parameter.

  • defaultValue – [in] The default value to use. If std::nullopt, then the parameter is required. If a required param is not found, a GetParamException is thrown.

  • unit – [in] Optional string serving as a [physical/SI] unit of the parameter, just to make the messages more informative.

  • options – [in] Options specifying detailed behavior of this function. Use the braced initializer syntax for comfortable writing, e.g. {.throwIfConvertFails = true, .allowNestedParams = false}.

Returns:

The loaded parameter value.