How to dynamically iterate over BTreeMap forwards or in reverse?

Question

Depending on a variable, I would like to iterate over a BTreeMap forwards or in reverse like so (playground):

pub enum Direction {
    Forwards,
    Backwards,
}

pub fn main() {
    use std::collections::BTreeMap;

    let direction = Direction::Forwards;

    // type inference lets us omit an explicit type signature (which
    // would be `BTreeMap<&str, &str>` in this example).
    let mut movie_reviews = BTreeMap::new();

    // review some movies.
    movie_reviews.insert("Office Space", "Deals with real issues in the workplace.");
    movie_reviews.insert("Pulp Fiction", "Masterpiece.");
    movie_reviews.insert("The Godfather", "Very enjoyable.");
    movie_reviews.insert("The Blues Brothers", "Eye lyked it a lot.");

    let iter = match direction {
        Direction::Forwards => movie_reviews.iter_mut(),
        Direction::Backwards => movie_reviews.iter_mut().rev(),
    };

    for (title, desc) in iter {
        println!("{}: {}", title, desc)
    }
}

However the match doesn't have the same type and errors:

error[E0308]: `match` arms have incompatible types
  --> src/main.rs:23:33
   |
21 |       let iter = match direction {
   |  ________________-
22 | |         Direction::Forwards => movie_reviews.iter_mut(),
   | |                                ------------------------ this is found to be of type `std::collections::btree_map::IterMut<'_, &str, &str>`
23 | |         Direction::Backwards => movie_reviews.iter_mut().rev(),
   | |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `std::collections::btree_map::IterMut`, found struct `Rev`
24 | |     };
   | |_____- `match` arms have incompatible types
   |
   = note: expected type `std::collections::btree_map::IterMut<'_, _, _>`
            found struct `Rev<std::collections::btree_map::IterMut<'_, _, _>>`

How can I dynamically decide which direction to iterate in?