How to work with deserialized?

[makorne]

Hi! Thank you for your great crates!!

Please add to end of your serde example how to iter over deserialized Enum and change values of structs. Something like this dummy-code:

    let mut deserialized:  Enum  = serde_json::from_str(&serialized).unwrap();
    println!("{:?}", &deserialized);
    for item in deserialized.iter(){
        println!("{:?}", &item);
        item.power = 10;
    }

[ryo33]

Something like this would work: deserialized.iter_mut().filter_map(AsVariantMut::<Items>::as_variant_mut)

I'll try add that later!

[makorne]

Looks like .iter_mut() does not exist

deserialized.iter_mut().filter_map(AsVariantMut::<Player>::as_variant_mut);
                      ^^^^^^^^ method not found in `Enum`

[ryo33]

I misinterpreted the code as Vec<Enum>. Correct is something like for item in enum.downcast_mut::<Items>().iter_mut().map(|items| &mut items.vec).flatten().

[makorne]

That does not work too.

413 | enum Enum {
    | --------- method `downcast_mut` not found for this enum
...
461 |     deserialized.downcast_mut::<Item>().iter_mut().flatten();
    |                  ^^^^^^^^^^^^
    |
help: there is a method `enum_downcast_mut` with a similar name
    |
461 |     deserialized.enum_downcast_mut::<Item>().iter_mut().flatten();

Items:

error[E0412]: cannot find type `Items` in this scope
   --> src/main.rs:462:50
    |
410 | struct Item(String);
    | -------------------- similarly named struct `Item` defined here
...
462 |     let found = deserialized.enum_downcast_mut::<Items>().iter_mut().flatten();
    |                                                  ^^^^^
    |
help: there is an enum variant `crate::Enum::Items`; try using the variant's enum
    |
462 |     let found = deserialized.enum_downcast_mut::<crate::Enum>().iter_mut().flatten();
    |                                                  ~~~~~~~~~~~
help: a struct with a similar name exists
    |
462 |     let found = deserialized.enum_downcast_mut::<Item>().iter_mut().flatten();

Item:

deserialized.enum_downcast_mut::<Item>().iter_mut().flatten();
    |                              ^^^^^^^^^^^^^^^^^ the trait `AsVariantMut<Item>` is not implemented for `Enum`
    |
    = help: the following other types implement trait `AsVariantMut<T>`:
              <Enum as AsVariantMut<Enemy>>
              <Enum as AsVariantMut<Player>>
              <Enum as AsVariantMut<Vec<Item>>>
note: required by a bound in `enum_downcast_mut`

[ryo33]

Sorry my example was wrong.

I've added the following. Can you try that for loop with enum_downcast_mut instead of `enum_downcast_ref? https://github.com/ryo33/enum_downcast/blob/main/examples/basic.rs#L56-L62

[makorne]

enum_downcast_mut works.

But loop over Items only. How to loop over Player and Enemy too?