Addition of Asserts for special data types XINT, UXINT, XWORD?

[AndyP01]

Could it be beneficial to add asserts for the special data types XINT, UXINT and XWORD?

See here:
https://infosys.beckhoff.com/english.php?content=../content/1033/tc3_plc_intro/2529448075.html&id=

[sagatowski]

I think it's a good idea. I'll create an issue from this.

[sagatowski]

Issue created. See #165.

[sagatowski]

Fixed links :-)

[sagatowski]

@AndyP01 If you have time, you are of course welcome to create a PR for this!