use crate::{Slice, SliceBorrowed, SliceOwned};
macro_rules! map {
($owned:ident, $in:ty, $fn:ident) => {
paste::paste! {
#[doc = "Maps using a closure on index; see [`" [<Slice $owned>] "::map`]."]
#[derive(Clone, Copy, Hash)]
pub struct [<Map $owned>]<S, F>(pub S, pub F);
impl<S, F, U> Slice for [<Map $owned>]<S, F>
where
S: [<Slice $owned>],
F: Fn($in) -> U,
{
type Output = U;
fn len(&self) -> usize {
self.0.len()
}
fn get_with<W: FnMut(&Self::Output) -> R, R>(&self, index: usize, f: &mut W) -> Option<R> {
Some(f(&self.get_owned(index)?))
}
}
impl<S, F, U> SliceOwned for [<Map $owned>]<S, F>
where
S: [<Slice $owned>],
F: Fn($in) -> U,
{
fn get_owned(&self, index: usize) -> Option<U> {
self.0.$fn(index).map(&self.1)
}
}
}
};
}
map!(Owned, S::Output, get_owned);
map!(Borrowed, &S::Output, get);