# the following code to fetch googletest
# is inspired by and adapted after https://crascit.com/2015/07/25/cmake-gtest/
# download and unpack googletest at configure time

macro(fetch_googletest _download_module_path _download_root)
    set(GOOGLETEST_DOWNLOAD_ROOT ${_download_root})
    configure_file(
        ${_download_module_path}/googletest-download.cmake
        ${_download_root}/CMakeLists.txt
        @ONLY
        )
    unset(GOOGLETEST_DOWNLOAD_ROOT)

    execute_process(
        COMMAND
            "${CMAKE_COMMAND}" -G "${CMAKE_GENERATOR}" .
        WORKING_DIRECTORY
            ${_download_root}
        )
    execute_process(
        COMMAND
            "${CMAKE_COMMAND}" --build .
        WORKING_DIRECTORY
            ${_download_root}
        )

if (MSVC)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /D_SILENCE_TR1_NAMESPACE_DEPRECATION_WARNING")
    set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
endif()

    # adds the targers: gtest, gtest_main, gmock, gmock_main
    add_subdirectory(
        ${_download_root}/googletest-src
        ${_download_root}/googletest-build
        EXCLUDE_FROM_ALL
        )
endmacro()