docker pull gcc
用vscode右击 run interactive
安装vim， cmake

CMakeLists.txt

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
set(PREBUILT_MODULE_PATH ${CMAKE_BINARY_DIR}/modules)

function(add_module name)
    file(MAKE_DIRECTORY ${PREBUILT_MODULE_PATH})
    add_custom_target(${name}.pcm
            COMMAND
                ${CMAKE_CXX_COMPILER}
                -std=c++20
                -fmodules-ts
                -c
                ${CMAKE_CURRENT_SOURCE_DIR}/${ARGN}
                -o ${PREBUILT_MODULE_PATH}/${name}.pcm

            )
endfunction()


add_compile_options(-fmodules-ts)

add_module(helloworld helloworld.cpp)
add_executable(main
        main.cpp
        helloworld.cpp
        )
add_dependencies(main helloworld.pcm)

helloworld.cpp

export module helloworld; // module declaration
 
import <iostream>;        // import declaration
 
export void hello()       // export declaration
{
    std::cout << "Hello world!\n";
}

main.cpp

import helloworld; // import declaration
 
int main()
{
    hello();
}

cmake .
 make
[  0%] Built target helloworld.pcm
[100%] Built target main
root@9627fdd8de4c:/gf/cpp# 

root@9627fdd8de4c:/gf/cpp# ./main
Hello world!