1#[macro_export]
2macro_rules! bitfield {
3 ($get:ident,$set:ident,$type:ty,$bitnum:expr,$bitwidth:expr) => {
4 pub fn $get(&self) -> $type {
5 let mask: $type = ((1 << $bitwidth) - 1) << $bitnum;
6 (self.value & mask) >> $bitnum
7 }
8 pub fn $set(&mut self, value: $type) {
9 let mask: $type = ((1 << $bitwidth) - 1) << $bitnum;
10 self.value = (self.value & !mask) | (value << $bitnum);
11 }
12 }
13}
14
15#[test]
16fn single_bit() {
17 struct Single {
18 pub value: u64
19 }
20 impl Single {
21 bitfield!(get_bit, set_bit, u64, 5, 1);
22 }
23
24 let mut test: Single = Single { value: 0 };
25 assert_eq!(test.get_bit(), 0);
26 test.set_bit(1u64);
27 assert_eq!(test.get_bit(), 1);
28 assert_eq!(test.value,1 << 5);
29 test.set_bit(0u64);
30 assert_eq!(test.get_bit(), 0);
31 assert_eq!(test.value,0);
32}
33
34#[test]
35fn multiple_bit() {
36 struct Multi {
37 pub value: u64
38 }
39 impl Multi {
40 bitfield!(get_bits, set_bits, u64, 5, 2);
41 }
42
43 let mut test: Multi = Multi { value: 0 };
44 assert_eq!(test.get_bits(), 0);
45 test.set_bits(1u64);
46 assert_eq!(test.get_bits(), 1);
47 assert_eq!(test.value,1 << 5);
48 test.set_bits(0u64);
49 assert_eq!(test.get_bits(), 0);
50 test.set_bits(2u64);
51 assert_eq!(test.get_bits(), 2);
52 assert_eq!(test.value,2 << 5);
53 test.set_bits(3u64);
54 assert_eq!(test.get_bits(), 3);
55 assert_eq!(test.value,3 << 5);
56}