//! Macro for generating pseudo-enums for type-level programming.
//! This is somewhat like https://github.com/fmease/tylift but implemented with `macro_rules!` syntax
//! ```
//! # use enum_to_types::enum_to_types;
//! # use std::marker::PhantomData;
//! enum_to_types!(AccessLevel; User, Admin);
//!
//! struct DataStorage<T: AccessLevel::AccessLevel>(i32, PhantomData<T>);
//!
//! impl<T: AccessLevel::AccessLevel> DataStorage<T> {
//!     fn new(i: i32) -> Self {
//!         Self(i, PhantomData)
//!     }
//! }
//!
//! trait ReadStorage<T: AccessLevel::AccessLevel> {
//!     fn read(&self) -> i32;
//! }
//!
//! impl ReadStorage<AccessLevel::Admin> for DataStorage<AccessLevel::User> {
//!     fn read(&self) -> i32 {
//!         self.0
//!     }
//! }
//!
//! impl ReadStorage<AccessLevel::User> for DataStorage<AccessLevel::User> {
//!     fn read(&self) -> i32 {
//!         self.0
//!     }
//! }
//!
//! impl ReadStorage<AccessLevel::Admin> for DataStorage<AccessLevel::Admin> {
//!     fn read(&self) -> i32 {
//!         self.0
//!     }
//! }
//!
//! impl ReadStorage<AccessLevel::User> for DataStorage<AccessLevel::Admin> {
//!     fn read(&self) -> i32 {
//!         panic!("You have no rights to read this");
//!     }
//! }
//!
//! fn main() {
//!     let storage = DataStorage::<AccessLevel::Admin>::new(1);
//!     assert_eq!(<DataStorage::<AccessLevel::Admin> as ReadStorage<AccessLevel::Admin>>::read(&storage), 1);
//!     let storage = DataStorage::<AccessLevel::User>::new(5);
//!     assert_eq!(<DataStorage::<AccessLevel::User> as ReadStorage<AccessLevel::User>>::read(&storage), 5);
//!     // reading storage with `AccessLevel::Admin` by user will cause panic
//! }
//! ```
//! This may look very verbose but it gives a lot of flexibility.
//! Also, other examples can look less verbose.

/// Macro for generating pseudo-enums for type-level programming.
/// This is somewhat like https://github.com/fmease/tylift but implemented with `macro_rules!` syntax
/// ```
/// # use enum_to_types::enum_to_types;
/// # use std::marker::PhantomData;
/// enum_to_types!(AccessLevel; User, Admin);
///
/// struct DataStorage<T: AccessLevel::AccessLevel>(i32, PhantomData<T>);
///
/// impl<T: AccessLevel::AccessLevel> DataStorage<T> {
///     fn new(i: i32) -> Self {
///         Self(i, PhantomData)
///     }
/// }
///
/// trait ReadStorage<T: AccessLevel::AccessLevel> {
///     fn read(&self) -> i32;
/// }
///
/// impl ReadStorage<AccessLevel::Admin> for DataStorage<AccessLevel::User> {
///     fn read(&self) -> i32 {
///         self.0
///     }
/// }
///
/// impl ReadStorage<AccessLevel::User> for DataStorage<AccessLevel::User> {
///     fn read(&self) -> i32 {
///         self.0
///     }
/// }
///
/// impl ReadStorage<AccessLevel::Admin> for DataStorage<AccessLevel::Admin> {
///     fn read(&self) -> i32 {
///         self.0
///     }
/// }
///
/// impl ReadStorage<AccessLevel::User> for DataStorage<AccessLevel::Admin> {
///     fn read(&self) -> i32 {
///         panic!("You have no rights to read this");
///     }
/// }
///
/// fn main() {
///     let storage = DataStorage::<AccessLevel::Admin>::new(1);
///     assert_eq!(<DataStorage::<AccessLevel::Admin> as ReadStorage<AccessLevel::Admin>>::read(&storage), 1);
///     let storage = DataStorage::<AccessLevel::User>::new(5);
///     assert_eq!(<DataStorage::<AccessLevel::User> as ReadStorage<AccessLevel::User>>::read(&storage), 5);
///     // reading storage with `AccessLevel::Admin` by user will cause panic
/// }
/// ```
/// This may look very verbose but it gives a lot of flexibility.
/// Also, other examples can look less verbose.
#[macro_export]
macro_rules! enum_to_types {
    ($name:ident; $($variant:ident),+) => {
        pub mod $name {
            pub trait $name {}
            $(
                #[derive(Debug, Ord, Hash, Eq, PartialOrd, PartialEq)]
                pub struct $variant;
                impl $name for $variant {}
            )+
        }
    };
}
