Unit testing of private methods [duplicate]

Answer 1

Make the test class as the friend of the original class. This friend declaration will be inside the #define UNIT_TEST flag.

class To_test_class {
   #ifdef UNIT_TEST
     friend test_class;
   #endif
}

Now for your unit test you will compile the code with flag -DUNIT_TEST. This way you will be able to test the private function.

Now your unit test code will not be pushed into production environment, as UNIT_TEST flag will be false. Hence the code is still secure.

Also you will not need any special library for unit testing.