as_box()
boxes its input only if it is not already a box. The
class is also checked if supplied.
as_box_if()
boxes its input only if it not already a box, or if
the predicate .p
returns TRUE
.
as_box(x, class = NULL)as_box_if(.x, .p, .class = NULL, ...)
An R object.
A box class. If the input is already a box of
that class, it is returned as is. If the input needs to be boxed,
class
is passed to new_box()
.
A predicate function.
Arguments passed to .p
.