The version of callOnPathSteps without an actual instance was completely
ignoring the upcasted type of `UpcastablePointer`s. We now fix this by
calling the right template specialization, which we choose by inspecting
the key of the `UpcastablePointer`.
This commit introduces the type system of the model along with several
various other improvements to the model and its users.
* Introduce the type system.
* Introduce possibility to tag certain fields in the model as to be
optional during YAML serialization.
* All the `Name` fields have been replaced in favor of `CustomName` plus
a `name` method that will use `CustomName` if available, or an
automatically generated name otherwise.
* Make TupleTreeReferences behavior more robust: now you either need to
have a valid pointer to `Root` and a `Path` or be default constructed
(`nullptr` for `Root` and an empty `Path`). Any other configuration is
invalid.
* The type system introduces `RawFunctionType`: this superseds the
previous way in which we were specifying arguments and return
values. Users of such information have been updated accordingly.
Add a specialization for
CallByPathVisitorWithInstance::visitContainerElement to handle cases
where the element of the container is an UpcastablePointer, that needs
to be unwrapped before visiting.
This fixes a problem causing bad TupleTree traversal with
TupleTreeReference. Specifically, CallByPathVisitorWithInstance did not
know how to visitContainerElement when the element of the container was
an UpcastablePointer. This caused the visit to always return nullptr
even when the TupleTreeReference was well-formed. This has been fixed by
adding an overload with proper concept constraint, that teaches
CallByPathVisitorWithInstance how to properly traverse
UpcastablePointers.
Antonio Frighetto