addition: automatic cpm download

CMakeLists.txt

@@ -11,6 +11,28 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 option(GRAPH_BUILD_TESTS "Build arraylist tests" OFF)
 option(GRAPH_ENABLE_SANITIZERS "Enable sanitizers for tests" ON)
 
+# --------------------------------------------------
+# CPM.cmake bootstrap
+# --------------------------------------------------
+
+set(CPM_DOWNLOAD_VERSION 0.40.2)
+
+set(CPM_DOWNLOAD_LOCATION
+    "${CMAKE_BINARY_DIR}/cmake/CPM.cmake"
+)
+
+if(NOT EXISTS ${CPM_DOWNLOAD_LOCATION})
+    message(STATUS "Downloading CPM.cmake...")
+
+    file(
+        DOWNLOAD
+        https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+        ${CPM_DOWNLOAD_LOCATION}
+    )
+endif()
+
+include(${CPM_DOWNLOAD_LOCATION})
+
 include(cmake/CPM.cmake)
 
 CPMAddPackage(