Using an Enum as a Key

The easiest way to expose an enum is to derive num_traits::FromPrimitive and num_traits::ToPrimitive using num-derive, and add an impl EnumKey line:

#[derive(Serialize, Deserialize, Eq, PartialEq, Debug, Key, Clone)]
pub enum Category {

The View code remains unchanged, although the associated Key type can now be set to Option<Category>. The queries can now use the enum instead of a String:

    let rust_post_count = db

BonsaiDb will convert the enum to a u64 and use that value as the Key. A u64 was chosen to ensure fairly wide compatibility even with some extreme usages of bitmasks. If you wish to customize this behavior, you can implement Key directly.