make install looks working

CMakeLists.txt

-project(matplotlibcpp17)
 cmake_minimum_required(VERSION 3.12)
 
+project(
+  "matplotlibcpp17"
+  VERSION 0.0.0
+  DESCRIPTION "A C++ header-only plotting library based on pybind11 and matplotlib, featuring more flexibility than matplotlibcpp"
+  HOMEPAGE_URL "https://soblin.github.io/matplotlibcpp17/"
+  )
+
 find_package(Python3 COMPONENTS Interpreter Development NumPy)
 find_package(pybind11 REQUIRED)
 
-if(NOT DEFINED ADD_DEMO)
-  set(ADD_DEMO ON)
-endif()
+set(matplotlibcpp17_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include")
 
+# gallery
 if(NOT DEFINED USE_GUI)
   set(USE_GUI 0)
 endif()
-
-set(matplotlibcpp17_INCLUDE_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/include")
+if(NOT DEFINED ADD_DEMO)
+  set(ADD_DEMO ON)
+endif()
 
 function(add_demo name path)
   add_executable(${name} ${path})
@@ -39,10 +45,52 @@ if(${ADD_DEMO})
   add_subdirectory(gallery/mplot3d)
 endif()
 
+
+# test
 if(NOT DEFINED DO_TEST)
   set(DO_TEST ON)
 endif()
-
 if(${DO_TEST})
   add_subdirectory(tests)
 endif()
+
+
+# install
+## https://dominikberner.ch/cmake-interface-lib/
+include(GNUInstallDirs)
+add_library(${PROJECT_NAME} INTERFACE)
+target_include_directories(${PROJECT_NAME}
+  INTERFACE
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+  )
+target_compile_features(${PROJECT_NAME} INTERFACE cxx_std_17)
+install(TARGETS ${PROJECT_NAME}
+  EXPORT ${PROJECT_NAME}_Targets
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  )
+include(CMakePackageConfigHelpers)
+write_basic_package_version_file("${PROJECT_NAME}ConfigVersion.cmake"
+  VERSION ${PROJECT_VERSION}
+  COMPATIBILITY SameMajorVersion
+  )
+configure_package_config_file(
+  "${PROJECT_SOURCE_DIR}/cmake/${PROJECT_NAME}Config.cmake.in"
+  "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
+  INSTALL_DESTINATION
+  ${CMAKE_INSTALL_DATAROOTDIR}/${PROJECT_NAME}/cmake
+  )
+install(EXPORT ${PROJECT_NAME}_Targets
+  FILE ${PROJECT_NAME}Targets.cmake
+  NAMESPACE ${PROJECT_NAME}::
+  DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/${PROJECT_NAME}/cmake
+  )
+install(FILES
+  "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
+  "${PROJECT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
+  DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/cmake
+  )
+install(DIRECTORY ${PROJECT_SOURCE_DIR}/include/${PROJECT_NAME}
+  DESTINATION include
+  )

cmake/matplotlibcpp17Config.cmake.in

+@PACKAGE_INIT@
+
+include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
+check_required_components("@PROJECT_NAME@")