Object Toolkit - C++ standard and its violations.

Hello Guys. We are struggling a bit with some "not very good" practices that are implemented  by PTC in C++ Object Toolkit API.

First is bad&ugly define which collides with default type from standard library. So inside of  ciptype.h at line 68 we have 

# define optional

which obviously is in conflict with std::optional (see cppreference)

Second a bit strange approach we may find in: cipxobj.h and xstring.h both at line 17

using namespace std;
 

According to not only CPP reference but to well known best practices it's bad idea:

(see cppreference)

The using-directive using namespace std; at any namespace scope introduces every name from the namespace std into the global namespace (since the global namespace is the nearest namespace that contains both std and any user-declared namespace), which may lead to undesirable name collisions. This, and other using directives are generally considered bad practice at file scope of a header file (SF.7: Don’t write using namespace at global scope in a header file).

We use Creo Parametric 10.0.5.0  but issue exits there for many years and when C++ 17  standard appeared this become more painful. 

Please PTC, remove those lines from your API and make it more modern (and user friendly)