From fe30fcd228ff95be1f169f580b30184c8511d1c3 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 16 Apr 2019 17:34:06 -0400
Subject: [PATCH] Use hb_deref_pointer() to reduce number of overloads

---
 src/hb-algs.hh | 27 ++++++++++-----------------
 src/hb-meta.hh | 36 +++++++++++++++++++-----------------
 2 files changed, 29 insertions(+), 34 deletions(-)

diff --git a/src/hb-algs.hh b/src/hb-algs.hh
index c21d8634e..6b80a61f9 100644
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@@ -72,21 +72,18 @@ struct
 
   /* Pointer-to-member-function. */
   template <typename Appl, typename Val> auto
-  impl (Appl&& a, Val &&v, hb_priority<5>) const HB_AUTO_RETURN_EXPR (hb_forward<Val> (v).*a ())
-  template <typename Appl, typename Val> auto
-  impl (Appl&& a, Val &&v, hb_priority<4>) const HB_AUTO_RETURN_EXPR (hb_forward<Val> (v)->*a ())
+  impl (Appl&& a, Val &&v, hb_priority<2>) const HB_AUTO_RETURN_EXPR
+  (hb_forward<Val> (hb_deref_pointer (v)).*a ())
 
   /* Pointer-to-member. */
   template <typename Appl, typename Val> auto
-  impl (Appl&& a, Val &&v, hb_priority<3>) const HB_AUTO_RETURN_EXPR (hb_forward<Val> (v).*a)
-  template <typename Appl, typename Val> auto
-  impl (Appl&& a, Val &&v, hb_priority<2>) const HB_AUTO_RETURN_EXPR (hb_forward<Val> (v)->*a)
+  impl (Appl&& a, Val &&v, hb_priority<1>) const HB_AUTO_RETURN_EXPR
+  (hb_forward<Val> (hb_deref_pointer (v)).*a)
 
   /* Operator(). */
   template <typename Appl, typename Val> auto
-  impl (Appl&& a, Val &&v, hb_priority<1>) const HB_AUTO_RETURN_EXPR (a (hb_forward<Val> (v)))
-  template <typename Appl, typename Val> auto
-  impl (Appl&& a, Val &&v, hb_priority<0>) const HB_AUTO_RETURN_EXPR ((*a) (hb_forward<Val> (v)))
+  impl (Appl&& a, Val &&v, hb_priority<0>) const HB_AUTO_RETURN_EXPR
+  (hb_deref_pointer (a) (hb_forward<Val> (v)))
 
   public:
 
@@ -104,10 +101,8 @@ struct
   private:
 
   template <typename Pred, typename Val> auto
-  impl (Pred&& p, Val &&v, hb_priority<2>) const HB_AUTO_RETURN_EXPR (p->has (v))
-
-  template <typename Pred, typename Val> auto
-  impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN_EXPR (p.has (v))
+  impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN_EXPR
+  (hb_deref_pointer (p).has (v))
 
   template <typename Pred, typename Val> auto
   impl (Pred&& p, Val &&v, hb_priority<0>) const HB_AUTO_RETURN_EXPR
@@ -132,10 +127,8 @@ struct
   private:
 
   template <typename Proj, typename Val> auto
-  impl (Proj&& f, Val &&v, hb_priority<2>) const HB_AUTO_RETURN_EXPR (f->get (hb_forward<Val> (v)))
-
-  template <typename Proj, typename Val> auto
-  impl (Proj&& f, Val &&v, hb_priority<1>) const HB_AUTO_RETURN_EXPR (f.get (hb_forward<Val> (v)))
+  impl (Proj&& f, Val &&v, hb_priority<1>) const HB_AUTO_RETURN_EXPR
+  (hb_deref_pointer (f).get (hb_forward<Val> (v)))
 
   template <typename Proj, typename Val> auto
   impl (Proj&& f, Val &&v, hb_priority<0>) const HB_AUTO_RETURN_EXPR
diff --git a/src/hb-meta.hh b/src/hb-meta.hh
index a5edd0372..5698250fc 100644
--- a/src/hb-meta.hh
+++ b/src/hb-meta.hh
@@ -34,6 +34,15 @@
  * C++ template meta-programming & fundamentals used with them.
  */
 
+/* Function overloading SFINAE and priority. */
+
+#define HB_AUTO_RETURN_EXPR(E) -> decltype ((E)) { return (E); }
+#define HB_VOID_RETURN_EXPR(E) -> hb_void_tt<decltype ((E))> { (E); }
+
+template <unsigned Pri> struct hb_priority : hb_priority<Pri - 1> {};
+template <>             struct hb_priority<0> {};
+#define hb_prioritize hb_priority<16> ()
+
 #define HB_FUNCOBJ(x) static_const x HB_UNUSED
 
 struct
@@ -67,14 +76,6 @@ template <typename T> struct hb_match_pointer<T *> { typedef T type; enum { valu
 template <typename T> using hb_remove_pointer = typename hb_match_pointer<T>::type;
 #define hb_is_pointer(T) hb_match_pointer<T>::value
 
-struct
-{
-  template <typename T>
-  T operator () (T v) const { return v; }
-  template <typename T>
-  T& operator () (T *v) const { return *v; }
-} HB_FUNCOBJ (hb_deref_pointer);
-
 
 /* std::move and std::forward */
 
@@ -86,6 +87,16 @@ static T&& hb_forward (hb_remove_reference<T>& t) { return (T&&) t; }
 template <typename T>
 static T&& hb_forward (hb_remove_reference<T>&& t) { return (T&&) t; }
 
+struct
+{
+  template <typename T> auto
+  operator () (T&& v) const HB_AUTO_RETURN_EXPR (hb_forward<T> (v))
+
+  template <typename T> auto
+  operator () (T *v) const HB_AUTO_RETURN_EXPR (*v)
+
+} HB_FUNCOBJ (hb_deref_pointer);
+
 
 /* Void!  For when we need a expression-type of void. */
 struct hb_void_t { typedef void value; };
@@ -140,14 +151,5 @@ template <> struct hb_is_integer<signed long long> { enum { value = true }; };
 template <> struct hb_is_integer<unsigned long long> { enum { value = true }; };
 #define hb_is_integer(T) hb_is_integer<T>::value
 
-/* Function overloading SFINAE and priority. */
-
-#define HB_AUTO_RETURN_EXPR(E) -> decltype ((E)) { return (E); }
-#define HB_VOID_RETURN_EXPR(E) -> hb_void_tt<decltype ((E))> { (E); }
-
-template <unsigned Pri> struct hb_priority : hb_priority<Pri - 1> {};
-template <>             struct hb_priority<0> {};
-#define hb_prioritize hb_priority<16> ()
-
 
 #endif /* HB_META_HH */