proc_bitfield/example/
support.rs

1#[cfg(feature = "nightly")]
2use super::UnwrapBitsExample;
3use crate::conv::UnsafeFrom;
4pub use core::num::TryFromIntError;
5
6/// Wrapper around [`NonZeroU8`](core::num::NonZeroU8) to implement conversion traits on a foreign
7/// type.
8#[derive(Clone, Copy, Debug)]
9pub struct NonZeroU8(core::num::NonZeroU8);
10
11impl From<NonZeroU8> for u8 {
12    fn from(other: NonZeroU8) -> Self {
13        other.0.into()
14    }
15}
16
17impl TryFrom<u8> for NonZeroU8 {
18    type Error = TryFromIntError;
19
20    fn try_from(other: u8) -> Result<Self, Self::Error> {
21        Ok(NonZeroU8(other.try_into()?))
22    }
23}
24
25impl UnsafeFrom<u8> for NonZeroU8 {
26    unsafe fn unsafe_from(other: u8) -> Self {
27        NonZeroU8(core::num::NonZeroU8::new_unchecked(other))
28    }
29}
30
31/// Wrapper around [`u16`] to implement conversion traits on a foreign type.
32#[derive(Clone, Copy, Debug)]
33pub struct U16(pub u16);
34
35impl UnsafeFrom<U16> for u8 {
36    unsafe fn unsafe_from(other: U16) -> Self {
37        other.0 as u8
38    }
39}
40
41impl TryFrom<U16> for u8 {
42    type Error = TryFromIntError;
43
44    fn try_from(other: U16) -> Result<Self, Self::Error> {
45        other.0.try_into()
46    }
47}
48
49/// Wrapper around [`u8`] with infallible conversions both ways.
50#[derive(Clone, Copy, Debug)]
51pub struct U8WithParity {
52    pub raw: u8,
53    pub has_even_set_bits: bool,
54}
55
56impl From<u8> for U8WithParity {
57    fn from(other: u8) -> Self {
58        U8WithParity {
59            raw: other,
60            has_even_set_bits: other.count_ones() & 1 == 0,
61        }
62    }
63}
64
65impl From<U8WithParity> for u8 {
66    fn from(other: U8WithParity) -> Self {
67        other.raw
68    }
69}
70
71/// Wrapper around [`u8`] with fallible and unsafe conversion options both ways.
72#[derive(Clone, Copy, Debug)]
73pub struct SpuriouslyFailingU8(u8);
74
75impl TryFrom<u8> for SpuriouslyFailingU8 {
76    type Error = ();
77
78    fn try_from(other: u8) -> Result<Self, Self::Error> {
79        // Doesn't actually fail, but in real-world code this function could fail depending on
80        // external factors
81        Ok(SpuriouslyFailingU8(other))
82    }
83}
84
85impl UnsafeFrom<u8> for SpuriouslyFailingU8 {
86    unsafe fn unsafe_from(other: u8) -> Self {
87        SpuriouslyFailingU8(other)
88    }
89}
90
91impl TryFrom<SpuriouslyFailingU8> for u8 {
92    type Error = ();
93
94    fn try_from(other: SpuriouslyFailingU8) -> Result<Self, Self::Error> {
95        // Same as above
96        Ok(other.0)
97    }
98}
99
100impl UnsafeFrom<SpuriouslyFailingU8> for u8 {
101    unsafe fn unsafe_from(other: SpuriouslyFailingU8) -> Self {
102        other.0
103    }
104}
105
106#[cfg(feature = "nightly")]
107impl TryFrom<u8> for UnwrapBitsExample {
108    type Error = ();
109
110    fn try_from(other: u8) -> Result<Self, Self::Error> {
111        match NonZeroU8::try_from(other) {
112            Ok(v) => Ok(UnwrapBitsExample(v)),
113            Err(_) => Err(()),
114        }
115    }
116}
117
118#[cfg(feature = "nightly")]
119impl From<UnwrapBitsExample> for u8 {
120    fn from(other: UnwrapBitsExample) -> Self {
121        other.0.into()
122    }
123}
proc_bitfield/example/support.rs

proc_bitfield/example/
support.rs
