
can override arg in OOB conditions
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> with_subscript_data(vec_slice(set_names(letters), "foo"), NULL)
Error: Can't subset elements that don't exist.
x The element `foo` doesn't exist.

> with_subscript_data(vec_slice(set_names(letters), "foo"), "input")
Error: Can't subset elements that don't exist.
x The element `foo` doesn't exist.

> with_subscript_data(vec_slice(set_names(letters), "foo"), quote(input))
Error: Can't subset elements that don't exist.
x The element `foo` doesn't exist.

> with_subscript_data(vec_slice(set_names(letters), "foo"), quote(input[i]))
Error: Can't subset elements that don't exist.
x The element `foo` doesn't exist.

