Retrieving(get_parameter()) value of parameter of type std::vector<int> won't build
Pratham-Pandey opened this issue · 3 comments
Bug report
Required Info:
- Operating System:
- Ubuntu 22.04 MATE
- Installation type:
- binaries
- Version or commit hash:
- Iron
- DDS implementation:
- Default(have not changed it)
- Client library (if applicable):
- rclcpp
Steps to reproduce issue
- Create a ROS2 package
ros2 pkg create --build-type ament_cmake vector_int_pkg
- Create a simple node the declares a parameter of type std::vector in file src/test_vector_int.cpp
#include "rclcpp/rclcpp.hpp"
int main(int argc, char ** argv)
{
rclcpp::init(argc, argv);
std::shared_ptr<rclcpp::Node> node = rclcpp::Node::make_shared("vector_integer_parameters");
// Declaring Params
node->declare_parameter("param", std::vector<int>{});
// Getting Params
std::vector<int> clamps_iters = {1,2,3};
node->get_parameter("param", clamps_iters);
rclcpp::spin(node);
rclcpp::shutdown();
}
- Adjust the CMakeLists.txt file
cmake_minimum_required(VERSION 3.5)
project(vector_int_pkg)
if (NOT CMAKE_C_STANDARD)
set(CMAKE_C_STANDARD 99)
endif ()
if (NOT CMAKE_CXX_STANDARD)
set(CMAKE_CXX_STANDARD 14)
endif ()
if (CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
add_compile_options(-Wall -Wextra -Wpedantic)
endif ()
find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)
add_executable(test_vector_int src/test_vector_int.cpp)
ament_target_dependencies(test_vector_int rclcpp)
ament_package()
- Adjust the package.xml
<?xml version="1.0"?>
<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
<package format="3">
<name>vector_int_pkg</name>
<version>0.0.0</version>
<description>TODO: Package description</description>
<maintainer email="john@doe.com">John Doe</maintainer>
<license>TODO: License declaration</license>
<buildtool_depend>ament_cmake</buildtool_depend>
<depend>rclcpp</depend>
<test_depend>ament_lint_auto</test_depend>
<test_depend>ament_lint_common</test_depend>
<export>
<build_type>ament_cmake</build_type>
</export>
</package>
- Build the package
colcon build --packages-select vector_int_pkg
Expected behavior
The package should build successfully.
Actual behavior
The build fails with the following error:
/home/user/ros_ws/src/vector_int_pkg/src/test_vector_int.cpp:14:22: required from here
/opt/ros/iron/include/rclcpp/rclcpp/node_impl.hpp:343:17: error: no matching function for call to ‘std::vector<int>::vector(std::vector<long int, std::allocator<long int> >)’
343 | parameter = static_cast<ParameterT>(parameter_variant.get_value<ParameterT>());
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Additional information
The issue seems similar to #1585. The only difference is that issue was related to declaring parameter values and this one is related to retrieving values.
NOTE: The code in #1585 is building successfully on my system.
In ParameterValue, std::vector<int> and std::vector<int64_t> are of the same type.
rclcpp/rclcpp/src/rclcpp/parameter_value.cpp
Lines 188 to 198 in c743c17
Both are stored as std::vector<int64_t>.
The returned value when retrieving is also std::vector<int64_t>
rclcpp/rclcpp/include/rclcpp/parameter_value.hpp
Lines 305 to 313 in c743c17
A simple workaround is std::vector<int64_t> clamps_iters = {1,2,3};
Regarding the fix, I'm considering modifying get() for std::vector as the below
template<typename type>
typename std::enable_if<
std::is_convertible<
type, const std::vector<int> &>::value, const std::vector<int>>::type
get() const
{
std::vector<int> convert;
auto array = get<ParameterType::PARAMETER_INTEGER_ARRAY>();
convert.reserve(array.size());
for(const auto& val : array) {
convert.push_back(static_cast<int>(val));
}
return convert;
}Is there a better way?
In ParameterValue, std::vector and std::vector<int64_t> are of the same type.
- If both are of same type then what is the need of having 2 different functions?
- Could you explain the actual cause of the issue?
In ParameterValue, std::vector and std::vector<int64_t> are of the same type.
std::vector -> std:vector<int>
If both are of same type then what is the need of having 2 different functions?
Could you explain the actual cause of the issue?
I think you mean these 2 functions.
rclcpp/rclcpp/include/rclcpp/parameter_value.hpp
Lines 305 to 323 in c743c17
While executing node->get_parameter("param", clamps_iters);
Regardless of whether the type of clamps_iters is std::vector or std::vector<int64_t>, the function above returns the internally stored std::vector<int64_t>.
The issue lies in the static conversion here. While the type of clamps_iters is std::vector<int>, it wants to convert std::vector<int64_t> to std:vector<int>. But there's no default conversion function.
rclcpp/rclcpp/include/rclcpp/node_impl.hpp
Line 345 in c743c17