Necessary to define compiler version?

[christophfroehlich]

Is it necessary to define the compiler version in message-only packages like this one?
I thought no, according to the docs
https://docs.ros.org/en/rolling/Tutorials/Beginner-Client-Libraries/Custom-ROS2-Interfaces.html#id6
but here it is part of the CMake file
https://github.com/ros2/example_interfaces/blob/rolling/CMakeLists.txt#L5-L12
What is correct here?
Tbh I have no idea about how rosidl etc work

[sloretz]

Neither of these blocks are necessary:

This sets the default C++ standard. However, the default standard on Ubuntu Noble is already C++ 17

example_interfaces/CMakeLists.txt

Lines 6 to 9 in 7b6e468

	if(NOT CMAKE_CXX_STANDARD)
	set(CMAKE_CXX_STANDARD 17)
	set(CMAKE_CXX_STANDARD_REQUIRED ON)
	endif()

This adds some extra compiler warnings to catch more errors in CI

example_interfaces/CMakeLists.txt

Lines 10 to 12 in 7b6e468

	if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
	add_compile_options(-Wall -Wextra -Wpedantic)
	endif()

[christophfroehlich]

Thanks for your answer. Is GCC used at all during the build of the messages?

[sloretz]

Thanks for your answer. Is GCC used at all during the build of the messages?

Yes, theres a bunch of C and C++ generated code that gets compiled.