From 7f2d12fa7b03379437c6291c8a962aab73c3990e Mon Sep 17 00:00:00 2001
From: Reuben Gardos Reid <5456207+ReubenJ@users.noreply.github.com>
Date: Mon, 21 Sep 2026 12:44:13 +0200
Subject: [PATCH 1/2] fix: `Base._unsetindex!` -> `Base.unsetindex!`

Julia 1.14 introduced a public API for `Base._unsetindex!` and
adds a deprecation warning for the old, private `Base._unsetindex!`.
This change adds an `isdefined` check that uses the `Base.unsetindex!`
definition if it is present, and falls back to the `Base._unsetindex!`
definition if not.

Closes: #986.
---
 src/DataStructures.jl | 7 +++++++
 src/circ_deque.jl     | 4 ++--
 src/deque.jl          | 4 ++--
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/DataStructures.jl b/src/DataStructures.jl
index 5e5d767ec..4cfce3411 100644
--- a/src/DataStructures.jl
+++ b/src/DataStructures.jl
@@ -7,6 +7,13 @@ module DataStructures
 
     import Base.insert!
 
+    # public unsetindex! API introduced in 1.14 (julia#58943)
+    if isdefined(Base, :unsetindex!)
+        using Base: unsetindex!
+    else
+        unsetindex!(A, i) = Base._unsetindex!(A, i)
+    end
+
     using OrderedCollections
     using OrderedCollections: isordered
     export OrderedDict, OrderedSet, LittleDict
diff --git a/src/circ_deque.jl b/src/circ_deque.jl
index fcf303ca3..598409134 100644
--- a/src/circ_deque.jl
+++ b/src/circ_deque.jl
@@ -64,7 +64,7 @@ end
 
 @inline Base.@propagate_inbounds function Base.pop!(D::CircularDeque)
     v = last(D)
-    Base._unsetindex!(D.buffer, D.last) # see issue/884
+    unsetindex!(D.buffer, D.last) # see issue/884
     D.n -= 1
     tmp = D.last - 1
     D.last = ifelse(tmp < 1, D.capacity, tmp)
@@ -92,7 +92,7 @@ Remove the element at the front.
 """
 @inline Base.@propagate_inbounds function Base.popfirst!(D::CircularDeque)
     v = first(D)
-    Base._unsetindex!(D.buffer, D.first) # see issue/884
+    unsetindex!(D.buffer, D.first) # see issue/884
     D.n -= 1
     tmp = D.first + 1
     D.first = ifelse(tmp > D.capacity, 1, tmp)
diff --git a/src/deque.jl b/src/deque.jl
index d1b1bb163..b123bb263 100644
--- a/src/deque.jl
+++ b/src/deque.jl
@@ -297,7 +297,7 @@ function Base.pop!(d::Deque{T}) where T
     @assert rear.back >= rear.front
 
     @inbounds x = rear.data[rear.back]
-    Base._unsetindex!(rear.data, rear.back) # see issue/884
+    unsetindex!(rear.data, rear.back) # see issue/884
     rear.back -= 1
     if rear.back < rear.front
         if d.nblocks > 1
@@ -323,7 +323,7 @@ function Base.popfirst!(d::Deque{T}) where T
     @assert head.back >= head.front
 
     @inbounds x = head.data[head.front]
-    Base._unsetindex!(head.data, head.front) # see issue/884
+    unsetindex!(head.data, head.front) # see issue/884
     head.front += 1
     if head.back < head.front
         if d.nblocks > 1

From bbbead4936d15ee94a09100b7c702ff1f191f101 Mon Sep 17 00:00:00 2001
From: Reuben Gardos Reid <5456207+ReubenJ@users.noreply.github.com>
Date: Fri, 2 Oct 2026 08:35:02 +0200
Subject: [PATCH 2/2] Apply suggestion from @nsajko

Co-authored-by: Neven Sajko <prosaic.37-element@icloud.com>
---
 src/DataStructures.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/DataStructures.jl b/src/DataStructures.jl
index 4cfce3411..191a480c1 100644
--- a/src/DataStructures.jl
+++ b/src/DataStructures.jl
@@ -11,7 +11,7 @@ module DataStructures
     if isdefined(Base, :unsetindex!)
         using Base: unsetindex!
     else
-        unsetindex!(A, i) = Base._unsetindex!(A, i)
+        using Base: _unsetindex! as unsetindex!
     end
 
     using OrderedCollections