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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-07 05:48:48 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-07 05:48:48 +0000
commitef24de24a82fe681581cc130f342363c47c0969a (patch)
tree0d494f7e1a38b95c92426f58fe6eaa877303a86c /vendor/itertools-0.10.5/src/cons_tuples_impl.rs
parentReleasing progress-linux version 1.74.1+dfsg1-1~progress7.99u1. (diff)
downloadrustc-ef24de24a82fe681581cc130f342363c47c0969a.tar.xz
rustc-ef24de24a82fe681581cc130f342363c47c0969a.zip
Merging upstream version 1.75.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/itertools-0.10.5/src/cons_tuples_impl.rs')
-rw-r--r--vendor/itertools-0.10.5/src/cons_tuples_impl.rs64
1 files changed, 64 insertions, 0 deletions
diff --git a/vendor/itertools-0.10.5/src/cons_tuples_impl.rs b/vendor/itertools-0.10.5/src/cons_tuples_impl.rs
new file mode 100644
index 000000000..ae0f48f34
--- /dev/null
+++ b/vendor/itertools-0.10.5/src/cons_tuples_impl.rs
@@ -0,0 +1,64 @@
+
+macro_rules! impl_cons_iter(
+ ($_A:ident, $_B:ident, ) => (); // stop
+
+ ($A:ident, $($B:ident,)*) => (
+ impl_cons_iter!($($B,)*);
+ #[allow(non_snake_case)]
+ impl<X, Iter, $($B),*> Iterator for ConsTuples<Iter, (($($B,)*), X)>
+ where Iter: Iterator<Item = (($($B,)*), X)>,
+ {
+ type Item = ($($B,)* X, );
+ fn next(&mut self) -> Option<Self::Item> {
+ self.iter.next().map(|(($($B,)*), x)| ($($B,)* x, ))
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.iter.size_hint()
+ }
+ fn fold<Acc, Fold>(self, accum: Acc, mut f: Fold) -> Acc
+ where Fold: FnMut(Acc, Self::Item) -> Acc,
+ {
+ self.iter.fold(accum, move |acc, (($($B,)*), x)| f(acc, ($($B,)* x, )))
+ }
+ }
+
+ #[allow(non_snake_case)]
+ impl<X, Iter, $($B),*> DoubleEndedIterator for ConsTuples<Iter, (($($B,)*), X)>
+ where Iter: DoubleEndedIterator<Item = (($($B,)*), X)>,
+ {
+ fn next_back(&mut self) -> Option<Self::Item> {
+ self.iter.next().map(|(($($B,)*), x)| ($($B,)* x, ))
+ }
+ }
+
+ );
+);
+
+impl_cons_iter!(A, B, C, D, E, F, G, H, I, J, K, L,);
+
+/// An iterator that maps an iterator of tuples like
+/// `((A, B), C)` to an iterator of `(A, B, C)`.
+///
+/// Used by the `iproduct!()` macro.
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[derive(Debug)]
+pub struct ConsTuples<I, J>
+ where I: Iterator<Item=J>,
+{
+ iter: I,
+}
+
+impl<I, J> Clone for ConsTuples<I, J>
+ where I: Clone + Iterator<Item=J>,
+{
+ clone_fields!(iter);
+}
+
+/// Create an iterator that maps for example iterators of
+/// `((A, B), C)` to `(A, B, C)`.
+pub fn cons_tuples<I, J>(iterable: I) -> ConsTuples<I::IntoIter, J>
+ where I: IntoIterator<Item=J>
+{
+ ConsTuples { iter: iterable.into_iter() }
+}