From 69d9114b5372c1fcea5f20e75a187158c31c52f8 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Thu, 9 May 2019 15:24:14 -0700
Subject: [PATCH] [meta] Rewrite hb_is_cr_converitble

---
 src/hb-meta.hh | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/hb-meta.hh b/src/hb-meta.hh
index b906c5539..58852091f 100644
--- a/src/hb-meta.hh
+++ b/src/hb-meta.hh
@@ -116,18 +116,6 @@ template <typename T> using hb_remove_pointer = typename hb_match_pointer<T>::ty
 /* TODO Add feature-parity to std::decay. */
 template <typename T> using hb_decay = hb_remove_const<hb_remove_reference<T>>;
 
-#define hb_is_cr_convertible(From, To) \
-	( \
-	  hb_is_same (hb_decay<From>, hb_decay<To>) && \
-	  ( \
-	    hb_is_const (From) <= hb_is_const (To) && \
-	    hb_is_reference (From) >= hb_is_reference (To) \
-	  ) || ( \
-	    hb_is_const (To) && hb_is_reference (To) \
-	  ) \
-	)
-
-
 
 template<bool B, class T, class F>
 struct _hb_conditional { typedef T type; };
@@ -159,6 +147,16 @@ struct hb_is_convertible
 };
 #define hb_is_convertible(From,To) hb_is_convertible<From, To>::value
 
+template <typename From, typename To>
+struct hb_is_cr_convertible
+{
+  public:
+  static constexpr bool value =
+    hb_is_same (hb_decay<From>, hb_decay<To>) &&
+    (!hb_is_const (From) || hb_is_const (To)) &&
+    (!hb_is_reference (To) || hb_is_const (To) || hb_is_reference (To));
+};
+#define hb_is_cr_convertible(From,To) hb_is_cr_convertible<From, To>::value
 
 /* std::move and std::forward */