Macro define_pyclass_setattr_slot

macro_rules! define_pyclass_setattr_slot {
    (
        $set_trait:ident,
        $del_trait:ident,
        $set:ident,
        $del:ident,
        $set_error:expr,
        $del_error:expr,
        $generate_macro:ident,
        $slot:ident,
        $func_ty:ident,
    ) => { ... };
}

Macro which expands to three items

• Trait for a setitem dunder
• Trait for the corresponding delitem dunder
• A macro which will use dtolnay specialisation to generate the shared slot for the two dunders