This would allow Array functions to be able to accept arrays of tuples, e.g. `size` And also allow vectorization of things like a [7-parameter function, which would currently be too expensive to enumerate](https://discourse.mc-stan.org/t/testing-for-7-parameter-function-with-known-partials/27046/7?u=wardbrian)