addressing comments

tests/owner_tests.cpp

@@ -25,12 +25,13 @@
 //disable warnings from gtest
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wundef"
-#endif
+#endif // __clang__ || __GNUC__
+
 #if __clang__
 #pragma GCC diagnostic ignored "-Wglobal-constructors"
 #pragma GCC diagnostic ignored "-Wused-but-marked-unused"
 #pragma GCC diagnostic ignored "-Wcovered-switch-default"
-#endif
+#endif // __clang__
 
 #include <gtest/gtest.h>
 
@@ -62,4 +63,4 @@ TEST(owner_tests, check_pointer_constraint)
 
 #if __clang__ || __GNUC__
 #pragma GCC diagnostic pop
-#endif
+#endif // __clang__ || __GNUC__