set(CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API "2182bf5c-ef0d-489a-91da-49dbc3090d2a")
set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
# Default to C++ extensions being off. Clang's modules support have trouble
# with extensions right now.
set(CMAKE_CXX_EXTENSIONS OFF)
特别是第一行的 218 那堆数字，真不禁黑人问号脸。CMake 这是正常人设计出来的工具？还不如传统的 Make 直观。
