Because of this line, the package is not usable with C++20 code as template bind is deprecated now. (Similar issued solved in message generation for C++ in PR ros2/rosidl#564 )

I kind of want to write PR for this for rclcpp, but I am not sure I understand what is going on here.
Why is it typename std::allocator::template rebind::other in ther first place? Seems like using std::allocator< T > is what is actually wanted here (which corresponds to actual implementation of std:: I have - rebind is implemented just as a way to get std::allocator)

I believe I am missing something here? If not I will try to make PR assap

John