Is it possible to use rev() on a PyTupleIterator to achieve reverse iteration?

[AphrosDelos532]

Here is my code,

    let args_iter = args.iter().rev();

Then i got,

error[E0277]: the trait bound `types::tuple::PyTupleIterator<'_>: DoubleEndedIterator` is not satisfied
    --> src/lib.rs:431:21
     |
431  |     let args_iter = args.iter().rev();
     |                     ^^^^^^^^^^^ --- required by a bound introduced by this call
     |                     |
     |                     the trait `DoubleEndedIterator` is not implemented for `types::tuple::PyTupleIterator<'_>`
     |
note: required by a bound in `rev` 

[adamreichold]

We have not yet implemented DoubleEndedIterator for PyTupleIterator which should however be possible. I will open a PR to fix this.

As workaround, maybe PyTuple::as_slice would work for you? Or in the worst case, using PyTuple::get_item to manually index into the tuple?

[AphrosDelos532]

I do this by collecting the elements into a Vec. However, I anticipate there might be some additional overhead. I'm glad to hear that reverse iterator will be supported soon. Thank you for your help!

[adamreichold]

#3366 is that PR.