From f657ef7e57c889309c2d9d37934368ca255f9d5b Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Fri, 18 Nov 2022 19:17:03 -0700
Subject: [PATCH] [map] Allow std::move-ing keys into the map

---
 src/hb-map.hh   | 15 +++++++++------
 src/test-map.cc |  2 ++
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/hb-map.hh b/src/hb-map.hh
index f938757aa..5712eb03f 100644
--- a/src/hb-map.hh
+++ b/src/hb-map.hh
@@ -186,7 +186,7 @@ struct hb_hashmap_t
     {
       if (old_items[i].is_real ())
       {
-	set_with_hash (old_items[i].key,
+	set_with_hash (std::move (old_items[i].key),
 		       old_items[i].hash,
 		       std::move (old_items[i].value));
       }
@@ -199,7 +199,9 @@ struct hb_hashmap_t
   }
 
   template <typename VV>
-  bool set (K key, VV&& value) { return set_with_hash (key, hb_hash (key), std::forward<VV> (value)); }
+  bool set (const K &key, VV&& value) { return set_with_hash (hb_ridentity (key), hb_hash (key), std::forward<VV> (value)); }
+  template <typename VV>
+  bool set (K&& key, VV&& value) { return set_with_hash (std::move (key), hb_hash (key), std::forward<VV> (value)); }
 
   const V& get (K key) const
   {
@@ -208,7 +210,8 @@ struct hb_hashmap_t
     return item.is_real () && item == key ? item.value : item_t::default_value ();
   }
 
-  void del (K key) { set_with_hash (key, hb_hash (key), item_t::default_value (), true); }
+  void del (const K &key) { set_with_hash (hb_ridentity (key), hb_hash (key), item_t::default_value (), true); }
+  void del (K&& key) { set_with_hash (std::move (key), hb_hash (key), item_t::default_value (), true); }
 
   /* Has interface. */
   typedef const V& value_t;
@@ -320,8 +323,8 @@ struct hb_hashmap_t
 
   protected:
 
-  template <typename VV>
-  bool set_with_hash (K key, uint32_t hash, VV&& value, bool is_delete=false)
+  template <typename KK, typename VV>
+  bool set_with_hash (KK&& key, uint32_t hash, VV&& value, bool is_delete=false)
   {
     if (unlikely (!successful)) return false;
     if (unlikely ((occupancy + occupancy / 2) >= mask && !resize ())) return false;
@@ -337,7 +340,7 @@ struct hb_hashmap_t
 	population--;
     }
 
-    item.key = key;
+    item.key = std::forward<KK> (key);
     item.value = std::forward<VV> (value);
     item.hash = hash;
     item.set_used (true);
diff --git a/src/test-map.cc b/src/test-map.cc
index 6f382ba78..2f59779e2 100644
--- a/src/test-map.cc
+++ b/src/test-map.cc
@@ -224,6 +224,8 @@ main (int argc, char **argv)
   {
     hb_hashmap_t<hb::unique_ptr<hb_set_t>, hb::unique_ptr<hb_set_t>> m;
 
+    m.set (hb::unique_ptr<hb_set_t> (hb_set_get_empty ()),
+	   hb::unique_ptr<hb_set_t> (hb_set_get_empty ()));
     m.get (hb::unique_ptr<hb_set_t> (hb_set_get_empty ()));
     m.iter_ref ();
     m.keys_ref ();