Added GTest. Though a bit dirty

OpenCL-CLHPP-Examples/CMakeLists.txt

@@ -35,4 +35,19 @@ endfunction()
 
 foreach(EXAMPLE ${EXAMPLES-OPENCL-CPP})
 	add_subdirectory(./${EXAMPLE})
-endforeach()
+endforeach()
+
+include(FetchContent)
+FetchContent_Declare(
+  googletest
+  # Specify the commit you depend on and update it regularly.
+  URL https://github.com/google/googletest/archive/5376968f6948923e2411081fd9372e71a59d8e77.zip
+)
+# For Windows: Prevent overriding the parent project's compiler/linker settings
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+FetchContent_MakeAvailable(googletest)
+
+# Now simply link against gtest or gtest_main as needed. Eg
+add_executable(unit-test ${CMAKE_SOURCE_DIR}/unit-test/main.cpp)
+target_link_libraries(unit-test gtest_main)
+add_test(NAME example_test COMMAND unit-test)