From c335bf469f5f1103d5ddf76716f356d026cc30c0 Mon Sep 17 00:00:00 2001
From: Qunxin Liu <qxliu@google.com>
Date: Mon, 26 Sep 2022 13:01:20 -0700
Subject: [PATCH] support dereferencing shared_ptrs and unique_ptrs

---
 src/hb-meta.hh  | 12 ++++++++++++
 src/test-map.cc | 17 +++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/src/hb-meta.hh b/src/hb-meta.hh
index 1921ccbb6..52a6791e3 100644
--- a/src/hb-meta.hh
+++ b/src/hb-meta.hh
@@ -133,6 +133,18 @@ struct
 
   template <typename T> constexpr auto
   operator () (T *v) const HB_AUTO_RETURN (*v)
+
+  template <typename T> constexpr auto
+  operator () (const hb::shared_ptr<T>& v) const HB_AUTO_RETURN (*v)
+
+  template <typename T> constexpr auto
+  operator () (hb::shared_ptr<T>& v) const HB_AUTO_RETURN (*v)
+  
+  template <typename T> constexpr auto
+  operator () (const hb::unique_ptr<T>& v) const HB_AUTO_RETURN (*v)
+
+  template <typename T> constexpr auto
+  operator () (hb::unique_ptr<T>& v) const HB_AUTO_RETURN (*v)
 }
 HB_FUNCOBJ (hb_deref);
 
diff --git a/src/test-map.cc b/src/test-map.cc
index 473e8f4f6..357a8b01b 100644
--- a/src/test-map.cc
+++ b/src/test-map.cc
@@ -222,6 +222,23 @@ main (int argc, char **argv)
     hb::unique_ptr<hb_hashmap_t<int, int>> *v2;
     m.has (0, &v2);
   }
+  /* Test hashmap with complex shared_ptrs as keys. */
+  {
+    hb_hashmap_t<hb::shared_ptr<hb_map_t>, unsigned> m;
 
+    hb_map_t *m1 = hb_map_create ();
+    hb_map_t *m2 = hb_map_create ();
+    m1->set (1,3);
+    m2->set (1,3);
+
+    hb::shared_ptr<hb_map_t> p1 {m1};
+    hb::shared_ptr<hb_map_t> p2 {m2};
+    m.set (p1,1);
+    
+    assert (m.has (p2));
+
+    m1->set (2,4);
+    assert (!m.has (p2));
+  }
   return 0;
 }