1use crate::{Slice, SliceBorrowed, SliceOwned};
2
3macro_rules! map {
4 ($owned:ident, $in:ty, $fn:ident) => {
5 paste::paste! {
6 #[doc = "Maps using a closure on index; see [`" [<Slice $owned>] "::map`]."]
7 #[derive(Clone, Copy, Hash)]
8 pub struct [<Map $owned>]<S, F>(pub S, pub F);
9
10 impl<S, F, U> Slice for [<Map $owned>]<S, F>
11 where
12 S: [<Slice $owned>],
13 F: Fn($in) -> U,
14 {
15 type Output = U;
16
17 fn len(&self) -> usize {
18 self.0.len()
19 }
20
21 fn get_with<W: FnMut(&Self::Output) -> R, R>(&self, index: usize, f: &mut W) -> Option<R> {
22 Some(f(&self.get_owned(index)?))
23 }
24 }
25
26 impl<S, F, U> SliceOwned for [<Map $owned>]<S, F>
27 where
28 S: [<Slice $owned>],
29 F: Fn($in) -> U,
30 {
31 fn get_owned(&self, index: usize) -> Option<U> {
32 self.0.$fn(index).map(&self.1)
33 }
34 }
35 }
36 };
37}
38
39map!(Owned, S::Output, get_owned);
40map!(Borrowed, &S::Output, get);
41