option_operations/
div.rs

1//! Traits for the division [`OptionOperations`].
2
3use core::ops::{Div, DivAssign};
4
5use crate::{Error, OptionOperations};
6
7common_option_op!(
8    Div,
9    div,
10    division,
11    "
12# Panics
13
14Most implementations will panic if `rhs` is zero.
15",
16);
17
18impl_for_ints!(OptionOverflowingDiv, {
19    type Output = Self;
20    fn opt_overflowing_div(self, rhs: Self) -> Option<(Self::Output, bool)> {
21        Some(self.overflowing_div(rhs))
22    }
23});
24
25impl_for_ints!(OptionWrappingDiv, {
26    type Output = Self;
27    fn opt_wrapping_div(self, rhs: Self) -> Option<Self::Output> {
28        Some(self.wrapping_div(rhs))
29    }
30});
31
32option_op_checked!(
33    Div,
34    div,
35    division,
36    "- Returns `Err(Error::DivisionByZero)` if `rhs` is zero.",
37);
38
39impl_for_ints!(OptionCheckedDiv, {
40    type Output = Self;
41    fn opt_checked_div(self, rhs: Self) -> Result<Option<Self::Output>, Error> {
42        if rhs == 0 {
43            return Err(Error::DivisionByZero);
44        }
45        self.checked_div(rhs).ok_or(Error::Overflow).map(Some)
46    }
47});
48
49impl OptionCheckedDiv<u32> for core::time::Duration {
50    type Output = Self;
51    fn opt_checked_div(self, rhs: u32) -> Result<Option<Self::Output>, Error> {
52        if rhs == 0 {
53            return Err(Error::DivisionByZero);
54        }
55        self.checked_div(rhs).ok_or(Error::Overflow).map(Some)
56    }
57}
58
59#[cfg(test)]
60mod test {
61    use super::*;
62    use crate::OptionOperations;
63    use core::ops::{Div, DivAssign};
64
65    #[derive(Copy, Clone, Debug, PartialEq, PartialOrd)]
66    struct MyInt(i64);
67
68    impl OptionOperations for MyInt {}
69
70    impl Div<MyInt> for MyInt {
71        type Output = MyInt;
72
73        fn div(self, rhs: MyInt) -> MyInt {
74            MyInt(self.0.div(rhs.0))
75        }
76    }
77
78    impl Div<i64> for MyInt {
79        type Output = MyInt;
80
81        fn div(self, rhs: i64) -> MyInt {
82            MyInt(self.0.div(rhs))
83        }
84    }
85
86    impl DivAssign<MyInt> for MyInt {
87        fn div_assign(&mut self, rhs: MyInt) {
88            self.0.div_assign(rhs.0)
89        }
90    }
91
92    impl DivAssign<i64> for MyInt {
93        fn div_assign(&mut self, rhs: i64) {
94            self.0.div_assign(rhs)
95        }
96    }
97
98    impl OptionCheckedDiv for MyInt {
99        type Output = MyInt;
100        fn opt_checked_div(self, rhs: MyInt) -> Result<Option<Self::Output>, Error> {
101            self.0.opt_checked_div(rhs.0).map(|ok| ok.map(MyInt))
102        }
103    }
104
105    impl OptionCheckedDiv<i64> for MyInt {
106        type Output = MyInt;
107        fn opt_checked_div(self, rhs: i64) -> Result<Option<Self::Output>, Error> {
108            self.0.opt_checked_div(rhs).map(|ok| ok.map(MyInt))
109        }
110    }
111
112    impl OptionOverflowingDiv for MyInt {
113        type Output = MyInt;
114        fn opt_overflowing_div(self, rhs: MyInt) -> Option<(Self::Output, bool)> {
115            self.0
116                .opt_overflowing_div(rhs.0)
117                .map(|(val, flag)| (MyInt(val), flag))
118        }
119    }
120
121    impl OptionOverflowingDiv<i64> for MyInt {
122        type Output = MyInt;
123        fn opt_overflowing_div(self, rhs: i64) -> Option<(Self::Output, bool)> {
124            self.0
125                .opt_overflowing_div(rhs)
126                .map(|(val, flag)| (MyInt(val), flag))
127        }
128    }
129
130    impl OptionWrappingDiv for MyInt {
131        type Output = MyInt;
132        fn opt_wrapping_div(self, rhs: MyInt) -> Option<Self::Output> {
133            self.0.opt_wrapping_div(rhs.0).map(MyInt)
134        }
135    }
136
137    impl OptionWrappingDiv<i64> for MyInt {
138        type Output = MyInt;
139        fn opt_wrapping_div(self, rhs: i64) -> Option<Self::Output> {
140            self.0.opt_wrapping_div(rhs).map(MyInt)
141        }
142    }
143
144    const MY_MINUS_1: MyInt = MyInt(-1);
145    const MY_0: MyInt = MyInt(0);
146    const MY_1: MyInt = MyInt(1);
147    const MY_2: MyInt = MyInt(2);
148    const MY_5: MyInt = MyInt(5);
149    const MY_10: MyInt = MyInt(10);
150    const MY_MIN: MyInt = MyInt(i64::MIN);
151    const MY_HALF_MAX: MyInt = MyInt(i64::MAX / 2);
152    const MY_MAX: MyInt = MyInt(i64::MAX);
153    const SOME_MINUS_1: Option<MyInt> = Some(MY_MINUS_1);
154    const SOME_0: Option<MyInt> = Some(MY_0);
155    const SOME_1: Option<MyInt> = Some(MY_1);
156    const SOME_2: Option<MyInt> = Some(MY_2);
157    const SOME_5: Option<MyInt> = Some(MY_5);
158    const SOME_10: Option<MyInt> = Some(MY_10);
159    const SOME_MIN: Option<MyInt> = Some(MY_MIN);
160    const SOME_HALF_MAX: Option<MyInt> = Some(MY_HALF_MAX);
161    const SOME_MAX: Option<MyInt> = Some(MY_MAX);
162    const NONE: Option<MyInt> = None;
163
164    #[test]
165    fn div_my() {
166        assert_eq!(MY_5.opt_div(MY_1), SOME_5);
167        assert_eq!(SOME_10.opt_div(MY_2), SOME_5);
168        assert_eq!(MY_0.opt_div(SOME_1), SOME_0);
169        assert_eq!(MY_MAX.opt_div(&SOME_2), SOME_HALF_MAX);
170        assert_eq!(MY_1.opt_div(NONE), NONE);
171        assert_eq!(NONE.opt_div(MY_1), NONE);
172    }
173
174    #[test]
175    #[should_panic]
176    fn div_by_zero_my() {
177        let _ = SOME_10.opt_div(SOME_0);
178    }
179
180    #[test]
181    fn div_i64() {
182        assert_eq!(MY_5.opt_div(5), SOME_1);
183        assert_eq!(SOME_10.opt_div(MY_2), SOME_5);
184        assert_eq!(MY_0.opt_div(Some(1)), SOME_0);
185        assert_eq!(MY_MAX.opt_div(Some(2)), SOME_HALF_MAX);
186        assert_eq!(MY_1.opt_div(Option::<i64>::None), NONE);
187        assert_eq!(Option::<MyInt>::None.opt_div(MY_1), NONE);
188    }
189
190    #[test]
191    #[should_panic]
192    fn div_by_zero_i64() {
193        let _ = SOME_10.opt_div(Some(0));
194    }
195
196    #[test]
197    fn div_assign_my() {
198        let mut my = MY_5;
199        my.opt_div_assign(MY_1);
200        assert_eq!(my, MY_5);
201
202        let mut some = SOME_10;
203        some.opt_div_assign(MY_5);
204        assert_eq!(some, SOME_2);
205
206        let mut my = MY_0;
207        my.opt_div_assign(SOME_1);
208        assert_eq!(my, MY_0);
209
210        let mut my = MY_MAX;
211        my.opt_div_assign(&SOME_2);
212        assert_eq!(my, MY_HALF_MAX);
213
214        let mut my = MY_1;
215        my.opt_div_assign(NONE);
216        assert_eq!(my, MY_1);
217
218        let mut some = SOME_2;
219        some.opt_div_assign(SOME_1);
220        assert_eq!(some, SOME_2);
221
222        let mut some = SOME_10;
223        some.opt_div_assign(&SOME_2);
224        assert_eq!(some, SOME_5);
225
226        let mut some = SOME_1;
227        some.opt_div_assign(NONE);
228        assert_eq!(some, SOME_1);
229
230        let mut none = NONE;
231        none.opt_div_assign(SOME_1);
232        assert_eq!(none, NONE);
233
234        let mut none = NONE;
235        none.opt_div_assign(NONE);
236        assert_eq!(none, NONE);
237    }
238
239    #[test]
240    #[should_panic]
241    fn div_assign_by_zero_my() {
242        let mut some = SOME_10;
243        some.opt_div_assign(SOME_0);
244    }
245
246    #[test]
247    fn div_assign_i64() {
248        let mut my = MY_5;
249        my.opt_div_assign(1);
250        assert_eq!(my, MY_5);
251
252        let mut some = SOME_10;
253        some.opt_div_assign(5);
254        assert_eq!(some, SOME_2);
255
256        let mut my = MY_0;
257        my.opt_div_assign(1);
258        assert_eq!(my, MY_0);
259
260        let mut my = MY_MAX;
261        my.opt_div_assign(2);
262        assert_eq!(my, MY_HALF_MAX);
263
264        let mut my = MY_1;
265        my.opt_div_assign(Option::<i64>::None);
266        assert_eq!(my, MY_1);
267
268        let mut some = SOME_2;
269        some.opt_div_assign(1);
270        assert_eq!(some, SOME_2);
271
272        let mut some = SOME_1;
273        some.opt_div_assign(Option::<i64>::None);
274        assert_eq!(some, SOME_1);
275
276        let mut none = NONE;
277        none.opt_div_assign(1);
278        assert_eq!(none, NONE);
279
280        let mut none = NONE;
281        none.opt_div_assign(Option::<i64>::None);
282        assert_eq!(none, NONE);
283    }
284
285    #[test]
286    #[should_panic]
287    fn div_assign_by_zero_i64() {
288        let mut some = SOME_10;
289        some.opt_div_assign(Some(0));
290    }
291
292    #[test]
293    fn checked_div() {
294        assert_eq!(MY_2.opt_checked_div(MY_1), Ok(SOME_2));
295        assert_eq!(MY_10.opt_checked_div(SOME_5), Ok(SOME_2));
296        assert_eq!(MY_0.opt_checked_div(&SOME_1), Ok(SOME_0));
297        assert_eq!(MY_MAX.opt_checked_div(MY_2), Ok(SOME_HALF_MAX));
298        assert_eq!(MY_MAX.opt_checked_div(MY_0), Err(Error::DivisionByZero));
299        assert_eq!(MY_MIN.opt_checked_div(MY_MINUS_1), Err(Error::Overflow));
300
301        assert_eq!(SOME_2.opt_checked_div(MY_1), Ok(SOME_2));
302        assert_eq!(SOME_10.opt_checked_div(SOME_2), Ok(SOME_5));
303        assert_eq!(SOME_0.opt_checked_div(&SOME_1), Ok(SOME_0));
304
305        assert_eq!(SOME_MAX.opt_checked_div(MY_2), Ok(SOME_HALF_MAX));
306        assert_eq!(SOME_MAX.opt_checked_div(MY_0), Err(Error::DivisionByZero));
307        assert_eq!(SOME_MIN.opt_checked_div(MY_MINUS_1), Err(Error::Overflow));
308        assert_eq!(SOME_MAX.opt_checked_div(0), Err(Error::DivisionByZero));
309        assert_eq!(SOME_MIN.opt_checked_div(-1), Err(Error::Overflow));
310        assert_eq!(
311            SOME_MAX.opt_checked_div(Some(0)),
312            Err(Error::DivisionByZero)
313        );
314        assert_eq!(SOME_MIN.opt_checked_div(Some(-1)), Err(Error::Overflow));
315        assert_eq!(SOME_MAX.opt_checked_div(SOME_0), Err(Error::DivisionByZero));
316        assert_eq!(SOME_MIN.opt_checked_div(SOME_MINUS_1), Err(Error::Overflow));
317        assert_eq!(MY_MIN.opt_checked_div(NONE), Ok(None));
318        assert_eq!(NONE.opt_checked_div(SOME_MIN), Ok(None));
319    }
320
321    #[test]
322    fn overflowing_div() {
323        assert_eq!(MY_2.opt_overflowing_div(MY_1), Some((MY_2, false)));
324        assert_eq!(MY_0.opt_overflowing_div(MY_1), Some((MY_0, false)));
325        assert_eq!(MY_MAX.opt_overflowing_div(MY_2), Some((MY_HALF_MAX, false)));
326        assert_eq!(MY_MIN.opt_overflowing_div(MY_MINUS_1), Some((MY_MIN, true)));
327        assert_eq!(
328            SOME_MIN.opt_overflowing_div(MY_MINUS_1),
329            Some((MY_MIN, true))
330        );
331        assert_eq!(SOME_MIN.opt_overflowing_div(-1), Some((MY_MIN, true)));
332        assert_eq!(SOME_MIN.opt_overflowing_div(Some(-1)), Some((MY_MIN, true)));
333        assert_eq!(
334            SOME_MIN.opt_overflowing_div(&Some(-1)),
335            Some((MY_MIN, true))
336        );
337        assert_eq!(
338            MY_MIN.opt_overflowing_div(SOME_MINUS_1),
339            Some((MY_MIN, true))
340        );
341        assert_eq!(
342            MY_MIN.opt_overflowing_div(&SOME_MINUS_1),
343            Some((MY_MIN, true))
344        );
345        assert_eq!(MY_MIN.opt_overflowing_div(NONE), None);
346        assert_eq!(NONE.opt_overflowing_div(MY_MIN), None);
347    }
348
349    #[test]
350    fn wrapping_div() {
351        assert_eq!(MY_2.opt_wrapping_div(MY_1), SOME_2);
352        assert_eq!(MY_0.opt_wrapping_div(MY_1), SOME_0);
353        assert_eq!(MY_MIN.opt_wrapping_div(MY_MINUS_1), SOME_MIN);
354        assert_eq!(SOME_MIN.opt_wrapping_div(MY_MINUS_1), SOME_MIN);
355        assert_eq!(SOME_MIN.opt_wrapping_div(-1), SOME_MIN);
356        assert_eq!(SOME_MIN.opt_wrapping_div(Some(-1)), SOME_MIN);
357        assert_eq!(SOME_MIN.opt_wrapping_div(&Some(-1)), SOME_MIN);
358        assert_eq!(MY_MIN.opt_wrapping_div(SOME_MINUS_1), SOME_MIN);
359        assert_eq!(MY_MIN.opt_wrapping_div(&SOME_MINUS_1), SOME_MIN);
360        assert_eq!(MY_MIN.opt_wrapping_div(NONE), None);
361        assert_eq!(NONE.opt_wrapping_div(MY_MIN), None);
362    }
363}