Don't use static methods on classes

Yes one can do this.

class BASthread{
public:
   static long getThreadId();  // Get ID of current thread
};

But in the interests of making code which is accessible to the widest audience possible with as little cognitive load it’s better just to write the code as function like this:

long BASthreadId(); // Get ID of current thread

Then everyone can easily understand that this is just a function one can call from anywhere. They don’t need to be C++ experts or understand the three meanings of static.

This is better.

See reduce complexity by limiting use of features.

See don’t use => for Javascript anonymous functions.