mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Rewrite Iterator::unzip in terms of (A, B)::extend

Browse Source
This commit is contained in:
Sebastian Widua 2021-05-30 18:49:31 +02:00
parent 50568449cd
commit b5e92756b3
1 changed files with 3 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
library/core/src/iter/traits/iterator.rs
View File

@ -2819,28 +2819,9 @@ pub trait Iterator {
FromB: Default + Extend<B>, FromB: Default + Extend<B>,
Self: Sized + Iterator<Item = (A, B)>, Self: Sized + Iterator<Item = (A, B)>,
{ {
fn extend<'a, A, B>( let mut unzipped: (FromA, FromB) = Default::default();
ts: &'a mut impl Extend<A>, unzipped.extend(self);
us: &'a mut impl Extend<B>, unzipped
) -> impl FnMut((), (A, B)) + 'a {
move |(), (t, u)| {
ts.extend_one(t);
us.extend_one(u);
}
}
let mut ts: FromA = Default::default();
let mut us: FromB = Default::default();
let (lower_bound, _) = self.size_hint();
if lower_bound > 0 {
ts.extend_reserve(lower_bound);
us.extend_reserve(lower_bound);
}
self.fold((), extend(&mut ts, &mut us));
(ts, us)
} }
/// Creates an iterator which copies all of its elements. /// Creates an iterator which copies all of its elements.