4 files changed, 7 insertions, 5 deletions
diff --git a/library/alloc/src/collections/binary_heap/mod.rs b/library/alloc/src/collections/binary_heap/mod.rs
index 66573b90d..61c5950b0 100644
--- a/library/alloc/src/collections/binary_heap/mod.rs
+++ b/library/alloc/src/collections/binary_heap/mod.rs
@@ -434,8 +434,9 @@ impl<T: Ord> BinaryHeap<T> {
     /// heap.push(4);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_binary_heap_constructor", issue = "112353")]
     #[must_use]
-    pub fn new() -> BinaryHeap<T> {
+    pub const fn new() -> BinaryHeap<T> {
         BinaryHeap { data: vec![] }
     }
 
@@ -477,8 +478,9 @@ impl<T: Ord, A: Allocator> BinaryHeap<T, A> {
     /// heap.push(4);
     /// ```
     #[unstable(feature = "allocator_api", issue = "32838")]
+    #[rustc_const_unstable(feature = "const_binary_heap_constructor", issue = "112353")]
     #[must_use]
-    pub fn new_in(alloc: A) -> BinaryHeap<T, A> {
+    pub const fn new_in(alloc: A) -> BinaryHeap<T, A> {
         BinaryHeap { data: Vec::new_in(alloc) }
     }
 
diff --git a/library/alloc/src/collections/btree/dedup_sorted_iter.rs b/library/alloc/src/collections/btree/dedup_sorted_iter.rs
index 17ee78045..cd6a88f32 100644
--- a/library/alloc/src/collections/btree/dedup_sorted_iter.rs
+++ b/library/alloc/src/collections/btree/dedup_sorted_iter.rs
@@ -1,6 +1,6 @@
 use core::iter::Peekable;
 
-/// A iterator for deduping the key of a sorted iterator.
+/// An iterator for deduping the key of a sorted iterator.
 /// When encountering the duplicated key, only the last key-value pair is yielded.
 ///
 /// Used by [`BTreeMap::bulk_build_from_sorted_iter`][1].
diff --git a/library/alloc/src/collections/btree/map.rs b/library/alloc/src/collections/btree/map.rs
index 5481b327d..4bdd96395 100644
--- a/library/alloc/src/collections/btree/map.rs
+++ b/library/alloc/src/collections/btree/map.rs
@@ -669,7 +669,7 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// map.insert(1, "a");
     /// ```
     #[unstable(feature = "btreemap_alloc", issue = "32838")]
-    pub fn new_in(alloc: A) -> BTreeMap<K, V, A> {
+    pub const fn new_in(alloc: A) -> BTreeMap<K, V, A> {
         BTreeMap { root: None, length: 0, alloc: ManuallyDrop::new(alloc), _marker: PhantomData }
     }
 }
diff --git a/library/alloc/src/collections/btree/set.rs b/library/alloc/src/collections/btree/set.rs
index 9da230915..0e0355128 100644
--- a/library/alloc/src/collections/btree/set.rs
+++ b/library/alloc/src/collections/btree/set.rs
@@ -358,7 +358,7 @@ impl<T, A: Allocator + Clone> BTreeSet<T, A> {
     /// let mut set: BTreeSet<i32> = BTreeSet::new_in(Global);
     /// ```
     #[unstable(feature = "btreemap_alloc", issue = "32838")]
-    pub fn new_in(alloc: A) -> BTreeSet<T, A> {
+    pub const fn new_in(alloc: A) -> BTreeSet<T, A> {
         BTreeSet { map: BTreeMap::new_in(alloc) }
     }