Macro bit_fiddler::mask

macro_rules! mask {
    ([..$end: tt], $ty: ty) => { ... };
    ([$start: tt..], $ty: ty) => { ... };
    ([..], $ty: ty) => { ... };
    ([$start: tt..$end: tt], $ty: ty) => { ... };
    (rev [$start: tt..], $ty: ty) => { ... };
    (rev [..$end: tt], $ty: ty) => { ... };
    (rev [..], $ty: ty) => { ... };
    (rev [$start: tt..$end: tt], $ty: ty) => { ... };
    ([start = $start: tt, count = $count: tt], $ty: ty) => { ... };
    (rev [start = $start: tt, count = $count: tt], $ty: ty) => { ... };
}

Macro for getting a bit mask over the given range.

Example

use bit_fiddler::mask;

let mask = mask!([0..64], u64);
assert_eq!(mask, u64::MAX);

let bitmap: u8 = 0b_1010_1010;
let masked_bitmap = bitmap & mask!([0..4], u8);
assert_eq!(masked_bitmap, 0b_0000_1010);

let bitmap: u8 = 0b_1111_1111;
let masked_bitmap = bitmap & mask!([3..], u8);
assert_eq!(masked_bitmap, 0b_1111_1000);

let bitmap: u8 = 0b_1111_1111;
let masked_bitmap = bitmap & mask!(rev [0..4], u8);
assert_eq!(masked_bitmap, 0b_1111_0000);

let bitmap: u8 = 0b_1111_1111;
let masked_bitmap = bitmap & mask!([start = 3, count = 4], u8);
assert_eq!(masked_bitmap, 0b_0111_1000);