try to split CMakeLists

CMakeLists.txt

@@ -18,7 +18,10 @@ find_package(Python REQUIRED COMPONENTS Interpreter Development.Module)
 find_package(pybind11 CONFIG REQUIRED)
 find_package(CGAL REQUIRED COMPONENTS ImageIO)
 
-add_library(_cpp SHARED cpp/LabelledTetrahedralMesh.h cpp/LabelledTetrahedralMesh.cpp)
+# make cache variables for install destinations
+include(GNUInstallDirs)
+
+add_subdirectory(cpp)
 
 # Add a library using FindPython's tooling (pybind11 also provides a helper like
 # this)

cpp/CMakeLists.txt

+project(_cpp)
+
+set(${PROJECT_NAME}_HEADERS
+    LabelledTetrahedralMesh.h
+)
+
+set(${PROJECT_NAME}_SOURCES
+    LabelledTetrahedralMesh.cpp
+)
+
+add_library(${PROJECT_NAME} SHARED
+    ${${PROJECT_NAME}_HEADERS}
+    ${${PROJECT_NAME}_SOURCES}
+)
+
+install(TARGETS ${PROJECT_NAME} EXPORT _cpp_targets
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+)
\ No newline at end of file