CMakeLists.txt

cmake_minimum_required(VERSION 3.10)project(MyProject)set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED True)# 如果顶层 CMakeLists.txt 文件中使用了 add_subdirectory() 命令，CMake 会进入指定的子目录，并处理该目录中的 CMakeLists.txt 文件
add_subdirectory(src/math)add_executable(MyProject src/main.cpp)target_link_libraries(MyProject PRIVATE MathLibrary)

math/CMakeLists.txt

add_library(MathLibrary add.cpp)target_include_directories(MathLibrary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

cd build
cmake ..
cmake build .  
# or 
cmake build . --config Release