Unresolved external symbol on static class members

Question

Very simply put:

I have a class that consists mostly of static public members, so I can group similar functions together that still have to be called from other clas

Answer 1

If you are using C++ 17 you can just use the inline specifier (see https://stackoverflow.com/a/11711082/55721)

---

If using older versions of the C++ standard, you must add the definitions to match your declarations of X and Y

unsigned char test::X;
unsigned char test::Y;

somewhere. You might want to also initialize a static member

unsigned char test::X = 4;

and again, you do that in the definition (usually in a CXX file) not in the declaration (which is often in a .H file)