[meta] More rewrites

src/hb-meta.hh

@@ -75,8 +75,8 @@ template <>             struct hb_priority<0> {};
 #define HB_FUNCOBJ(x) static_const x HB_UNUSED
 
 
-template <typename T> struct hb_match_identity { typedef T type; };
-template <typename T> using hb_type_identity = typename hb_match_identity<T>::type;
+template <typename T> struct hb_type_identity_t { typedef T type; };
+template <typename T> using hb_type_identity = typename hb_type_identity_t<T>::type;
 
 struct
 {
@@ -97,14 +97,14 @@ HB_FUNCOBJ (hb_addressof);
 template <typename T> static inline T hb_declval ();
 #define hb_declval(T) (hb_declval<T> ())
 
-template <typename T> struct hb_match_const		{ typedef T type; static constexpr bool value = false; };
-template <typename T> struct hb_match_const<const T>	{ typedef T type; static constexpr bool value = true;  };
+template <typename T> struct hb_match_const		: hb_type_identity_t<T>, hb_bool_constant<false>{};
+template <typename T> struct hb_match_const<const T>	: hb_type_identity_t<T>, hb_bool_constant<true>	{};
 template <typename T> using hb_remove_const = typename hb_match_const<T>::type;
 template <typename T> using hb_add_const = const T;
 #define hb_is_const(T) hb_match_const<T>::value
-template <typename T> struct hb_match_reference		{ typedef T type; static constexpr bool value = false; };
-template <typename T> struct hb_match_reference<T &>	{ typedef T type; static constexpr bool value = true;  };
-template <typename T> struct hb_match_reference<T &&>	{ typedef T type; static constexpr bool value = true;  };
+template <typename T> struct hb_match_reference		: hb_type_identity_t<T>, hb_bool_constant<false>{};
+template <typename T> struct hb_match_reference<T &>	: hb_type_identity_t<T>, hb_bool_constant<true>	{};
+template <typename T> struct hb_match_reference<T &&>	: hb_type_identity_t<T>, hb_bool_constant<true>	{};
 template <typename T> using hb_remove_reference = typename hb_match_reference<T>::type;
 template <typename T> auto _hb_try_add_lvalue_reference (hb_priority<1>) -> hb_type_identity<T&>;
 template <typename T> auto _hb_try_add_lvalue_reference (hb_priority<0>) -> hb_type_identity<T>;
@@ -113,8 +113,8 @@ template <typename T> auto _hb_try_add_rvalue_reference (hb_priority<1>) -> hb_t
 template <typename T> auto _hb_try_add_rvalue_reference (hb_priority<0>) -> hb_type_identity<T>;
 template <typename T> using hb_add_rvalue_reference = decltype (_hb_try_add_rvalue_reference<T> (hb_prioritize));
 #define hb_is_reference(T) hb_match_reference<T>::value
-template <typename T> struct hb_match_pointer		{ typedef T type; static constexpr bool value = false; };
-template <typename T> struct hb_match_pointer<T *>	{ typedef T type; static constexpr bool value = true;  };
+template <typename T> struct hb_match_pointer		: hb_type_identity_t<T>, hb_bool_constant<false>{};
+template <typename T> struct hb_match_pointer<T *>	: hb_type_identity_t<T>, hb_bool_constant<true>	{};
 template <typename T> using hb_remove_pointer = typename hb_match_pointer<T>::type;
 template <typename T> auto _hb_try_add_pointer (hb_priority<1>) -> hb_type_identity<hb_remove_reference<T>*>;
 template <typename T> auto _hb_try_add_pointer (hb_priority<1>) -> hb_type_identity<T>;