Macro bitfield 

macro_rules! bitfield {
    ($(#[$attributes:meta])* $visibility:vis struct $name:ident($type:ty); $($fields:tt)*) => { ... };
    (@impl_range struct $name:ident($type:ty)) => { ... };
    (@fields @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, $getter:tt, $setter:tt: $($exprs:expr),*; $($rest:tt)*) => { ... };
    (@fields @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, from $from:ty, $getter:tt, $setter:tt: $($exprs:expr),*; $($rest:tt)*) => { ... };
    (@fields @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, into $into:ty, $getter:tt, $setter:tt: $($exprs:expr),*; $($rest:tt)*) => { ... };
    (@fields @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, from into $from_into:ty, $getter:tt, $setter:tt: $($exprs:expr),*; $($rest:tt)*) => { ... };
    (@fields @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, from $from:ty, into $into:ty, $getter:tt, $setter:tt: $($exprs:expr),*; $($rest:tt)*) => { ... };
    (@fields @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, $from:tt, $into:tt, $getter:tt, $setter:tt: $($exprs:expr),*; $($rest:tt)*) => { ... };
    (@fields @$variant:tt) => { ... };
    (@field @$variant:tt $(#[$attributes:meta])* $visibility:vis $type:ty, $from:tt, $into:tt, $getter:ident, $setter:ident: $($exprs:expr),*) => { ... };
    (@field @getter $(#[$attributes:meta])* $visibility:vis $type:ty, _, _, $getter:ident, _: $msb:expr, $lsb:expr) => { ... };
    (@field @getter $(#[$attributes:meta])* $visibility:vis $type:ty, $from:ty, $into:ty, $getter:ident, _: $msb:expr, $lsb:expr) => { ... };
    (@field @getter $(#[$attributes:meta])* $visibility:vis $type:ty, _, _, $getter:ident, _: $bit:expr) => { ... };
    (@field @getter $(#[$attributes:meta])* $visibility:vis $type:ty, $from:ty, $into:ty, $getter:ident, _: $bit:expr) => { ... };
    (@field @getter $(#[$attributes:meta])* $visibility:vis $type:ty, $from:tt, $into:tt, _, $setter:ident: $($exprs:expr),*) => { ... };
    (@field @setter $(#[$attributes:meta])* $visibility:vis $type:ty, _, _, _, $setter:ident: $msb:expr, $lsb:expr) => { ... };
    (@field @setter $(#[$attributes:meta])* $visibility:vis $type:ty, $from:ty, $into:ty, _, $setter:ident: $msb:expr, $lsb:expr) => { ... };
    (@field @setter $(#[$attributes:meta])* $visibility:vis $type:ty, _, _, _, $setter:ident: $bit:expr) => { ... };
    (@field @setter $(#[$attributes:meta])* $visibility:vis $type:ty, $from:ty, $into:ty, _, $setter:ident: $bit:expr) => { ... };
    (@field @setter $(#[$attributes:meta])* $visibility:vis $type:ty, $from:tt, $into:tt, $getter:ident, _: $($exprs:expr),*) => { ... };
}

This macro defines a new bitfield-like struct backed by a single uint-like type. A variable amount of getters and or setters can be specified on a bitwise level. Every operation automatically ensures that no bounds are being violated.

Example

#![feature(const_mut_refs)]
#![feature(const_trait_impl)]

use const_bitfield::bitfield;

bitfield! {
    pub struct BitField(u16);
    u8, field1, set_field1: 7, 0;   // u8 getter/setter for bits 0..=7
    bool, field2, set_field2: 8;    // bool getter/setter for bit 8
    bool, field3, _: 9;             // bool getter for bit 9
    bool, _, set_field4: 10;        // bool setter for bit 10
    u8, field5, _: 12, 11;          // u8 getter for bits 11..=12
    u8, _, set_field6: 15, 13;      // u8 setter for bits 13..=15
}