Macro bitfield 

macro_rules! bitfield {
    (
        $(#[$attr:meta])* $vis:vis struct $name:ident($storage:ty) { $($fields:tt)* }
    ) => { ... };
    (@core $(#[$attr:meta])* $vis:vis $name:ident $storage:ty) => { ... };
    (@fields $vis:vis $name:ident $storage:ty {
        $($(#[doc = $doc:expr])* $hi:literal:$lo:literal $field:ident
            $(?=> $try_into_type:ty)?
            $(=> $into_type:ty)?
        ;
        )*
    }
    ) => { ... };
    (
        @private_field_accessors $vis:vis $name:ident $storage:ty : $hi:tt:$lo:tt $field:ident
    ) => { ... };
    (
        @public_field_accessors $(#[doc = $doc:expr])* $vis:vis $name:ident $storage:ty :
            $hi:literal:$lo:literal $field:ident => $into_type:ty
    ) => { ... };
    (
        @public_field_accessors $(#[doc = $doc:expr])* $vis:vis $name:ident $storage:ty :
            $hi:tt:$lo:tt $field:ident ?=> $try_into_type:ty
    ) => { ... };
    (
        @public_field_accessors $(#[doc = $doc:expr])* $vis:vis $name:ident $storage:ty :
            $hi:tt:$lo:tt $field:ident
    ) => { ... };
    (@debug $name:ident { $($field:ident;)* }) => { ... };
}

Defines a bitfield struct with bounds-checked accessors for individual bit ranges.

See the kernel::bitfield module for full documentation and examples.