Felecarp

The solution above works fine. I will write a pull request. Maybe there will be a more elegant solution in the future using `TypeVarTuple` but it is not yet implemented...

Finally, I found another way to implement it which don't need to add the same instance of a component to many entities. the first idea item 1 | | character...

Is it like using multiple World instances (or multiple contexts in v3) but separate processors can share data ? So there will be far fewer use cases for multiple contexts.

Thanks for these reviews. I will see to them but not for several months.