enum_consts.rs

/// Aims to create enumerated constants.
/// # Example
/// ```
/// pub struct Foo;
/// impl Foo {
///     enum_consts! {
///         pub const: u32 =>
///         BAR,
///         BAZ,
///     }
/// }
///
/// pub struct Foo2;
/// impl Foo2 {
///     enum_consts! {
///         pub const: u32 = 15 =>
///         BAR,
///         BAZ,
///         SUPER_FOO,
///     }
/// }
/// ```
#[macro_export]
macro_rules! enum_consts {

    {$($flag:ident)+ : $ty:ty => $($name:ident),*} => {
        enum_consts! {$($flag)*: $ty = 0 => $($name),*}
    };
    {$($flag:ident)+ : $ty:ty => $($name:ident,)*} => {
        enum_consts! {$($flag)*: $ty => $($name),*}
    };
    {$($flag:ident)+ : $ty:ty = $val:expr => $name_1:ident $(,$name:ident)*} => {
        $($flag)* $name_1: $ty = $val;
        enum_consts! {$($flag)*: $ty = ($val + 1) => $($name),*}
    };
    {$($flag:ident)+ : $ty:ty = $val:expr => $($name:ident,)+ } => {
        enum_consts! {$($flag)*: $ty = $val => $($name),*}
    };
    {$($flag:ident)+ : $ty:ty = $val:expr => } => {};

}