cmake + c++20 in OSX + cmakelists

cmake_minimum_required (VERSION 3.0)
project (stats)

SET(SOURCE_DIR  "${PROJECT_SOURCE_DIR}/source")
SET(INCLUDE_DIR "${PROJECT_SOURCE_DIR}/include")

AUX_SOURCE_DIRECTORY(${SOURCE_DIR}  SOURCE_FILES)
AUX_SOURCE_DIRECTORY(${INCLUDE_DIR} HEADER_FILES)

include_directories(${INCLUDE_DIR})

add_library(stats SHARED ${SOURCE_FILES})

add_executable(test ${SOURCE_DIR}/test.cxx)
target_link_libraries(test stats)