From 950b36f95df23e2b11ef15351d0208699c7677ba Mon Sep 17 00:00:00 2001
From: Eli Youngs <eli.m.youngs@gmail.com>
Date: Sat, 10 Dec 2022 18:03:02 -0800
Subject: [PATCH] AK: Add a try_ensure() method to HashMap

---
 AK/HashMap.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/AK/HashMap.h b/AK/HashMap.h
index 2a036cc5ae..d4d56968e2 100644
--- a/AK/HashMap.h
+++ b/AK/HashMap.h
@@ -222,6 +222,17 @@ public:
         return find(key)->value;
     }
 
+    template<typename Callback>
+    ErrorOr<V> try_ensure(K const& key, Callback initialization_callback)
+    {
+        auto it = find(key);
+        if (it != end())
+            return it->value;
+        auto result = TRY(try_set(key, initialization_callback()));
+        VERIFY(result == HashSetResult::InsertedNewEntry);
+        return find(key)->value;
+    }
+
     [[nodiscard]] Vector<K> keys() const
     {
         Vector<K> list;