mycelium_bitfield/
example.rs

1use crate::FromBits;
2#[cfg(trace_macros)]
3trace_macros!(true);
4mod example_bitfield;
5#[cfg(trace_macros)]
6trace_macros!(false);
7pub use self::example_bitfield::ExampleBitfield;
8
9/// An example enum type implementing [`FromBits`].
10#[repr(u8)]
11#[derive(Debug)]
12pub enum TestEnum {
13    Foo = 0b00,
14    Bar = 0b01,
15    Baz = 0b10,
16    Qux = 0b11,
17}
18
19impl FromBits<u64> for TestEnum {
20    const BITS: u32 = 2;
21    type Error = core::convert::Infallible;
22
23    fn try_from_bits(bits: u64) -> Result<Self, Self::Error> {
24        Ok(match bits as u8 {
25            bits if bits == Self::Foo as u8 => Self::Foo,
26            bits if bits == Self::Bar as u8 => Self::Bar,
27            bits if bits == Self::Baz as u8 => Self::Baz,
28            bits if bits == Self::Qux as u8 => Self::Qux,
29            bits => unreachable!("all patterns are covered: {:#b}", bits),
30        })
31    }
32
33    fn into_bits(self) -> u64 {
34        self as u8 as u64
35    }
36}
37
38/// Another example enum type implementing [`FromBits`].
39///
40/// This one has a *fallible* [`FromBits::try_from_bits`] method, because some bit
41/// patterns are not valid enum variants.
42#[repr(u8)]
43#[derive(Debug)]
44pub enum AnotherTestEnum {
45    Alice = 0b1000,
46    Bob = 0b1100,
47    Charlie = 0b1110,
48}
49
50impl FromBits<u64> for AnotherTestEnum {
51    const BITS: u32 = 4;
52    type Error = &'static str;
53
54    fn try_from_bits(bits: u64) -> Result<Self, Self::Error> {
55        match bits as u8 {
56            bits if bits == Self::Alice as u8 => Ok(Self::Alice),
57            bits if bits == Self::Bob as u8 => Ok(Self::Bob),
58            bits if bits == Self::Charlie as u8 => Ok(Self::Charlie),
59            _ => Err("invalid bit pattern for `AnotherTestEnum`, expected \
60                one of `0b1000`, `0b1100`, or `0b1110`"),
61        }
62    }
63
64    fn into_bits(self) -> u64 {
65        self as u8 as u64
66    }
67}
mycelium_bitfield/example.rs

mycelium_bitfield/
example.rs
