Partial moves
Within the destructuring of a single variable, both by-move and
by-reference pattern bindings can be used at the same time. Doing
this will result in a partial move of the variable, which means
that parts of the variable will be moved while other parts stay. In
such a case, the parent variable cannot be used afterwards as a
whole, however the parts that are only referenced (and not moved)
can still be used.
(In this example, we store the age variable on the heap to
illustrate the partial move: deleting ref in the above code would
give an error as the ownership of person.age would be moved to the
variable age. If Person.age were stored on the stack, ref would
not be required as the definition of age would copy the data from
person.age without moving it.)