https://bugs.gentoo.org/894376
https://gitlab.gnome.org/GNOME/libgee/-/commit/2f0bbe8987e5eb1390b23ac531c971b202c2ef77

From 2f0bbe8987e5eb1390b23ac531c971b202c2ef77 Mon Sep 17 00:00:00 2001
From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Thu, 13 Apr 2023 23:43:03 +0200
Subject: [PATCH] Implementations of "G List.get()" should use non-nullable
 return as defined

--- a/gee/abstractlist.vala
+++ b/gee/abstractlist.vala
@@ -39,7 +39,7 @@ public abstract class Gee.AbstractList<G> : Gee.AbstractCollection<G>, List<G> {
 	/**
 	 * {@inheritDoc}
 	 */
-	public abstract new G? get (int index);
+	public abstract new G get (int index);
 
 	/**
 	 * {@inheritDoc}
--- a/gee/concurrentlist.vala
+++ b/gee/concurrentlist.vala
@@ -170,7 +170,7 @@ public class Gee.ConcurrentList<G> : AbstractList<G> {
 	/**
 	 * {@inheritDoc}
 	 */
-	public override G? get (int index) {
+	public override G get (int index) {
 		HazardPointer.Context ctx = new HazardPointer.Context ();
 		Utils.Misc.unused (ctx);
 		assert (index >= 0);
--- a/gee/readonlylist.vala
+++ b/gee/readonlylist.vala
@@ -74,7 +74,7 @@ internal class Gee.ReadOnlyList<G> : Gee.ReadOnlyCollection<G>, List<G> {
 	/**
 	 * {@inheritDoc}
 	 */
-	public new G? get (int index) {
+	public new G get (int index) {
 		return ((Gee.List<G>) _collection).get (index);
 	}
 
--- a/gee/unrolledlinkedlist.vala
+++ b/gee/unrolledlinkedlist.vala
@@ -158,7 +158,7 @@ public class Gee.UnrolledLinkedList<G> : AbstractBidirList<G>, Queue<G>, Deque<G
 		return new Iterator<G> (this);
 	}
 
-	public override G? get (int index) {
+	public override G get (int index) {
 		assert (index >= 0);
 		assert (index < this._size);
 
-- 
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