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//! # Documentation for Additional Attributes
//!
//! ## Attributes on Enums
//!
//! Strum supports several custom attributes to modify the generated code. At the enum level, the following attributes are supported:
//!
//! - `#[strum(serialize_all = "case_style")]` attribute can be used to change the case used when serializing to and deserializing
//! from strings. This feature is enabled by [withoutboats/heck](https://github.com/withoutboats/heck) and supported case styles are:
//!
//! - `camelCase`
//! - `PascalCase`
//! - `kebab-case`
//! - `snake_case`
//! - `SCREAMING_SNAKE_CASE`
//! - `SCREAMING-KEBAB-CASE`
//! - `lowercase`
//! - `UPPERCASE`
//! - `title_case`
//! - `mixed_case`
//! - `Train-Case`
//!
//! ```rust
//! use strum_macros;
//!
//! #[derive(Debug, Eq, PartialEq, strum_macros::Display)]
//! #[strum(serialize_all = "snake_case")]
//! enum Brightness {
//! DarkBlack,
//! Dim {
//! glow: usize,
//! },
//! #[strum(serialize = "bright")]
//! BrightWhite,
//! }
//!
//! assert_eq!(
//! String::from("dark_black"),
//! Brightness::DarkBlack.to_string().as_ref()
//! );
//! assert_eq!(
//! String::from("dim"),
//! Brightness::Dim { glow: 0 }.to_string().as_ref()
//! );
//! assert_eq!(
//! String::from("bright"),
//! Brightness::BrightWhite.to_string().as_ref()
//! );
//! ```
//!
//! - You can also apply the `#[strum(ascii_case_insensitive)]` attribute to the enum,
//! and this has the same effect of applying it to every variant.
//!
//! ## Attributes on Variants
//!
//! Custom attributes are applied to a variant by adding `#[strum(parameter="value")]` to the variant.
//!
//! - `serialize="..."`: Changes the text that `FromStr()` looks for when parsing a string. This attribute can
//! be applied multiple times to an element and the enum variant will be parsed if any of them match.
//!
//! - `to_string="..."`: Similar to `serialize`. This value will be included when using `FromStr()`. More importantly,
//! this specifies what text to use when calling `variant.to_string()` with the `Display` derivation, or when calling `variant.as_ref()` with `AsRefStr`.
//!
//! - `default`: Applied to a single variant of an enum. The variant must be a Tuple-like
//! variant with a single piece of data that can be created from a `&str` i.e. `T: From<&str>`.
//! The generated code will now return the variant with the input string captured as shown below
//! instead of failing.
//!
//! ```text
//! // Replaces this:
//! _ => Err(strum::ParseError::VariantNotFound)
//! // With this in generated code:
//! default => Ok(Variant(default.into()))
//! ```
//! The plugin will fail if the data doesn't implement From<&str>. You can only have one `default`
//! on your enum.
//!
//! - `transparent`: Signals that the inner field's implementation should be used, instead of generating
//! one for this variant. Only applicable to enum variants with a single field. Compatible with the
//! `AsRefStr`, `Display` and `IntoStaticStr` derive macros. Note that `IntoStaticStr` has a few restrictions,
//! the value must be `'static` and `const_into_str` is not supported in combination with `transparent` b/c
//! transparent relies on a call on `From::from(variant)`.
//!
//! - `disabled`: removes variant from generated code.
//!
//! - `ascii_case_insensitive`: makes the comparison to this variant case insensitive (ASCII only).
//! If the whole enum is marked `ascii_case_insensitive`, you can specify `ascii_case_insensitive = false`
//! to disable case insensitivity on this variant.
//!
//! - `message=".."`: Adds a message to enum variant. This is used in conjunction with the `EnumMessage`
//! trait to associate a message with a variant. If `detailed_message` is not provided,
//! then `message` will also be returned when `get_detailed_message` is called.
//!
//! - `detailed_message=".."`: Adds a more detailed message to a variant. If this value is omitted, then
//! `message` will be used in it's place.
//!
//! - Structured documentation, as in `/// ...`: If using `EnumMessage`, is accessible via get_documentation().
//!
//! - `props(key="value")`: Enables associating additional information with a given variant.