This commit is the first step towards building an operator builder that doesn't rely on holding on to Rc<RefCell<ChangeBatch<T>>.
In order to do so builder_ref::OperatorBuilder encodes the current shape of the operator in the type system by consuming self and producing a new builder type every time an input or output is added.
When the time comes to build the operator, the system requires the user to supply a closure whose type signature matches exactly the inputs and outputs have have been previously declared.
This PR only adds the typestate machinery to builder_ref::OperatorBuilder. A subsequent PR will work on removing
all the shared refcounted change batches since they now have a single owner. The reason this isn't included in this PR is to keep it at a reasonable size since many auxiliary types like the handles will need to be adjusted to work with references.
This commit is the first step towards building an operator builder that doesn't rely on holding on to
Rc<RefCell<ChangeBatch<T>>.In order to do so
builder_ref::OperatorBuilderencodes the current shape of the operator in the type system by consuming self and producing a new builder type every time an input or output is added.When the time comes to build the operator, the system requires the user to supply a closure whose type signature matches exactly the inputs and outputs have have been previously declared.
This PR only adds the typestate machinery to
builder_ref::OperatorBuilder. A subsequent PR will work on removing all the shared refcounted change batches since they now have a single owner. The reason this isn't included in this PR is to keep it at a reasonable size since many auxiliary types like the handles will need to be adjusted to work with references.