1//! Type-level bits.
2//!
3//! These are rather simple and are used as the building blocks of the
4//! other number types in this crate.
5//!
6//!
7//! **Type operators** implemented:
8//!
9//! - From `core::ops`: `BitAnd`, `BitOr`, `BitXor`, and `Not`.
10//! - From `typenum`: `Same` and `Cmp`.
11
12use crate::{private::InternalMarker, Cmp, Equal, Greater, Less, NonZero, PowerOfTwo, Zero};
13use core::ops::{BitAnd, BitOr, BitXor, Not};
14
15pub use crate::marker_traits::Bit;
16
17/// The type-level bit 0.
18#[derive(Eq, PartialEq, Ord, PartialOrd, Clone, Copy, Hash, Debug, Default)]
19#[cfg_attr(feature = "scale_info", derive(scale_info::TypeInfo))]
20pub struct B0;
21
22impl B0 {
23 /// Instantiates a singleton representing this bit.
24 #[inline]
25 pub fn new() -> B0 {
26 B0
27 }
28}
29
30/// The type-level bit 1.
31#[derive(Eq, PartialEq, Ord, PartialOrd, Clone, Copy, Hash, Debug, Default)]
32#[cfg_attr(feature = "scale_info", derive(scale_info::TypeInfo))]
33pub struct B1;
34
35impl B1 {
36 /// Instantiates a singleton representing this bit.
37 #[inline]
38 pub fn new() -> B1 {
39 B1
40 }
41}
42
43impl Bit for B0 {
44 const U8: u8 = 0;
45 const BOOL: bool = false;
46
47 #[inline]
48 fn new() -> Self {
49 Self
50 }
51 #[inline]
52 fn to_u8() -> u8 {
53 0
54 }
55 #[inline]
56 fn to_bool() -> bool {
57 false
58 }
59}
60
61impl Bit for B1 {
62 const U8: u8 = 1;
63 const BOOL: bool = true;
64
65 #[inline]
66 fn new() -> Self {
67 Self
68 }
69 #[inline]
70 fn to_u8() -> u8 {
71 1
72 }
73 #[inline]
74 fn to_bool() -> bool {
75 true
76 }
77}
78
79impl Zero for B0 {}
80impl NonZero for B1 {}
81impl PowerOfTwo for B1 {}
82
83/// Not of 0 (!0 = 1)
84impl Not for B0 {
85 type Output = B1;
86 #[inline]
87 fn not(self) -> Self::Output {
88 B1
89 }
90}
91/// Not of 1 (!1 = 0)
92impl Not for B1 {
93 type Output = B0;
94 #[inline]
95 fn not(self) -> Self::Output {
96 B0
97 }
98}
99
100/// And with 0 ( 0 & B = 0)
101impl<Rhs: Bit> BitAnd<Rhs> for B0 {
102 type Output = B0;
103 #[inline]
104 fn bitand(self, _: Rhs) -> Self::Output {
105 B0
106 }
107}
108
109/// And with 1 ( 1 & 0 = 0)
110impl BitAnd<B0> for B1 {
111 type Output = B0;
112 #[inline]
113 fn bitand(self, _: B0) -> Self::Output {
114 B0
115 }
116}
117
118/// And with 1 ( 1 & 1 = 1)
119impl BitAnd<B1> for B1 {
120 type Output = B1;
121 #[inline]
122 fn bitand(self, _: B1) -> Self::Output {
123 B1
124 }
125}
126
127/// Or with 0 ( 0 | 0 = 0)
128impl BitOr<B0> for B0 {
129 type Output = B0;
130 #[inline]
131 fn bitor(self, _: B0) -> Self::Output {
132 B0
133 }
134}
135
136/// Or with 0 ( 0 | 1 = 1)
137impl BitOr<B1> for B0 {
138 type Output = B1;
139 #[inline]
140 fn bitor(self, _: B1) -> Self::Output {
141 B1
142 }
143}
144
145/// Or with 1 ( 1 | B = 1)
146impl<Rhs: Bit> BitOr<Rhs> for B1 {
147 type Output = B1;
148 #[inline]
149 fn bitor(self, _: Rhs) -> Self::Output {
150 B1
151 }
152}
153
154/// Xor between 0 and 0 ( 0 ^ 0 = 0)
155impl BitXor<B0> for B0 {
156 type Output = B0;
157 #[inline]
158 fn bitxor(self, _: B0) -> Self::Output {
159 B0
160 }
161}
162/// Xor between 1 and 0 ( 1 ^ 0 = 1)
163impl BitXor<B0> for B1 {
164 type Output = B1;
165 #[inline]
166 fn bitxor(self, _: B0) -> Self::Output {
167 B1
168 }
169}
170/// Xor between 0 and 1 ( 0 ^ 1 = 1)
171impl BitXor<B1> for B0 {
172 type Output = B1;
173 #[inline]
174 fn bitxor(self, _: B1) -> Self::Output {
175 B1
176 }
177}
178/// Xor between 1 and 1 ( 1 ^ 1 = 0)
179impl BitXor<B1> for B1 {
180 type Output = B0;
181 #[inline]
182 fn bitxor(self, _: B1) -> Self::Output {
183 B0
184 }
185}
186
187#[cfg(test)]
188mod bit_op_tests {
189 use core::ops::{BitAnd, BitOr, BitXor, Not};
190
191 use crate::{B0, B1};
192
193 // macro for testing operation results. Uses `Same` to ensure the types are equal and
194 // not just the values they evaluate to.
195 macro_rules! test_bit_op {
196 ($op:ident $Lhs:ident = $Answer:ident) => {{
197 type Test = <<$Lhs as $op>::Output as $crate::Same<$Answer>>::Output;
198 assert_eq!(
199 <$Answer as $crate::Bit>::to_u8(),
200 <Test as $crate::Bit>::to_u8()
201 );
202 }};
203 ($Lhs:ident $op:ident $Rhs:ident = $Answer:ident) => {{
204 type Test = <<$Lhs as $op<$Rhs>>::Output as $crate::Same<$Answer>>::Output;
205 assert_eq!(
206 <$Answer as $crate::Bit>::to_u8(),
207 <Test as $crate::Bit>::to_u8()
208 );
209 }};
210 }
211
212 #[test]
213 fn bit_operations() {
214 test_bit_op!(Not B0 = B1);
215 test_bit_op!(Not B1 = B0);
216
217 test_bit_op!(B0 BitAnd B0 = B0);
218 test_bit_op!(B0 BitAnd B1 = B0);
219 test_bit_op!(B1 BitAnd B0 = B0);
220 test_bit_op!(B1 BitAnd B1 = B1);
221
222 test_bit_op!(B0 BitOr B0 = B0);
223 test_bit_op!(B0 BitOr B1 = B1);
224 test_bit_op!(B1 BitOr B0 = B1);
225 test_bit_op!(B1 BitOr B1 = B1);
226
227 test_bit_op!(B0 BitXor B0 = B0);
228 test_bit_op!(B0 BitXor B1 = B1);
229 test_bit_op!(B1 BitXor B0 = B1);
230 test_bit_op!(B1 BitXor B1 = B0);
231 }
232}
233
234impl Cmp<B0> for B0 {
235 type Output = Equal;
236
237 #[inline]
238 fn compare<P: InternalMarker>(&self, _: &B0) -> Self::Output {
239 Equal
240 }
241}
242
243impl Cmp<B1> for B0 {
244 type Output = Less;
245
246 #[inline]
247 fn compare<P: InternalMarker>(&self, _: &B1) -> Self::Output {
248 Less
249 }
250}
251
252impl Cmp<B0> for B1 {
253 type Output = Greater;
254
255 #[inline]
256 fn compare<P: InternalMarker>(&self, _: &B0) -> Self::Output {
257 Greater
258 }
259}
260
261impl Cmp<B1> for B1 {
262 type Output = Equal;
263
264 #[inline]
265 fn compare<P: InternalMarker>(&self, _: &B1) -> Self::Output {
266 Equal
267 }
268}
269
270use crate::Min;
271impl Min<B0> for B0 {
272 type Output = B0;
273 #[inline]
274 fn min(self, _: B0) -> B0 {
275 self
276 }
277}
278impl Min<B1> for B0 {
279 type Output = B0;
280 #[inline]
281 fn min(self, _: B1) -> B0 {
282 self
283 }
284}
285impl Min<B0> for B1 {
286 type Output = B0;
287 #[inline]
288 fn min(self, rhs: B0) -> B0 {
289 rhs
290 }
291}
292impl Min<B1> for B1 {
293 type Output = B1;
294 #[inline]
295 fn min(self, _: B1) -> B1 {
296 self
297 }
298}
299
300use crate::Max;
301impl Max<B0> for B0 {
302 type Output = B0;
303 #[inline]
304 fn max(self, _: B0) -> B0 {
305 self
306 }
307}
308impl Max<B1> for B0 {
309 type Output = B1;
310 #[inline]
311 fn max(self, rhs: B1) -> B1 {
312 rhs
313 }
314}
315impl Max<B0> for B1 {
316 type Output = B1;
317 #[inline]
318 fn max(self, _: B0) -> B1 {
319 self
320 }
321}
322impl Max<B1> for B1 {
323 type Output = B1;
324 #[inline]
325 fn max(self, _: B1) -> B1 {
326 self
327 }
328}
329
330#[cfg(test)]
331mod bit_creation_tests {
332 #[test]
333 fn bit_creation() {
334 {
335 use crate::{B0, B1};
336 let _: B0 = B0::new();
337 let _: B1 = B1::new();
338 }
339
340 {
341 use crate::{Bit, B0, B1};
342
343 let _: B0 = <B0 as Bit>::new();
344 let _: B1 = <B1 as Bit>::new();
345 }
346 }
347}
348