cmake HAS_REFERENCE examples

ginkgo-project/ginkgo test/test_install/CMakeLists.txt :30 

target_compile_definitions(test_install PRIVATE HAS_REFERENCE=${HAS_REFERENCE})

ginkgo-project/ginkgo test/test_install/CMakeLists.txt :46 

target_compile_definitions(
        test_install_cuda
        PRIVATE HAS_REFERENCE=${HAS_REFERENCE}
    )

ginkgo-project/ginkgo test/test_install/CMakeLists.txt :68 

target_compile_definitions(
        test_install_hip
        PRIVATE HAS_REFERENCE=${HAS_REFERENCE}
    )