abort_if_not            Ensure the truth of R expressions
are-bare-type-predicates
                        Bare type predicates
are-scalar-type-predicates
                        Scalar type predicates
are-type-predicates     Type predicates
are_empty               Are objects empty vectors or NULL?
are_integerish          Are vectors integer-like?
are_named               Are objects named?
are_true                Are objects TRUE or FALSE?
cast_if_not             Cast objects to a given type
enforce                 Ensure the truth of R expressions and
                        cast/recycle objects.
recycle_if_not          Recycle objects to a given size
schema                  Ensure the truth of data-masked R expressions
                        and cast/recycle named elements.
