set(CMAKE_EXPERIMENTAL_CXX_IMPORT_STD
  "0e5b6991-d74f-4b3d-a41c-cf096e0b2508")

cmake_language(GET_EXPERIMENTAL_FEATURE_ENABLED
  "CxxImportStd"
  feature_present)

if (NOT feature_present STREQUAL "TRUE")
  message(FATAL_ERROR
    "Expected the `CxxImportStd` feature to be enabled.")
endif ()