Don't expose ZipImpl to Iterator

src/libcore/iter/adapters/mod.rs

@@ -13,7 +13,6 @@ mod zip;
 pub use self::chain::Chain;
 pub use self::flatten::{FlatMap, Flatten};
 pub use self::zip::Zip;
-pub(super) use self::zip::ZipImpl;
 pub(crate) use self::zip::TrustedRandomAccess;
 
 /// A double-ended iterator with the direction inverted.

src/libcore/iter/adapters/zip.rs

@@ -19,6 +19,9 @@ pub struct Zip<A, B> {
     len: usize,
 }
 impl<A: Iterator, B: Iterator> Zip<A, B> {
+    pub(in super::super) fn new(a: A, b: B) -> Zip<A, B> {
+        ZipImpl::new(a, b)
+    }
     fn super_nth(&mut self, mut n: usize) -> Option<(A::Item, B::Item)> {
         while let Some(x) = Iterator::next(self) {
             if n == 0 { return Some(x) }
@@ -62,7 +65,7 @@ impl<A, B> DoubleEndedIterator for Zip<A, B> where
 
 // Zip specialization trait
 #[doc(hidden)]
-pub(in super::super) trait ZipImpl<A, B> {
+trait ZipImpl<A, B> {
     type Item;
     fn new(a: A, b: B) -> Self;
     fn next(&mut self) -> Option<Self::Item>;

src/libcore/iter/mod.rs

@@ -353,7 +353,6 @@ pub use self::adapters::Flatten;
 #[unstable(feature = "iter_copied", issue = "57127")]
 pub use self::adapters::Copied;
 
-use self::adapters::ZipImpl;
 pub(crate) use self::adapters::TrustedRandomAccess;
 
 mod range;

src/libcore/iter/traits/iterator.rs

@@ -5,8 +5,7 @@ use super::super::LoopState;
 use super::super::{Chain, Cycle, Copied, Cloned, Enumerate, Filter, FilterMap, Fuse};
 use super::super::{Flatten, FlatMap};
 use super::super::{Inspect, Map, Peekable, Scan, Skip, SkipWhile, StepBy, Take, TakeWhile, Rev};
-use super::super::{Zip, Sum, Product};
-use super::super::{FromIterator, ZipImpl};
+use super::super::{Zip, Sum, Product, FromIterator};
 
 fn _assert_is_object_safe(_: &dyn Iterator<Item=()>) {}