[meta] Rewrite is_signed, add is_unsigned

diff --git a/src/hb-meta.hh b/src/hb-meta.hh
index 6f141e0..7b4d026 100644 (file)
--- a/src/hb-meta.hh
+++ b/src/hb-meta.hh
@@ -251,24 +251,19 @@ using hb_is_arithmetic = hb_bool_constant<
   hb_is_floating_point (T) ||
   false
 >;
-#define hb_is_arighmetic(T) hb_is_arighmetic<T>::value
-
-template <typename T> struct hb_is_signed;
-template <> struct hb_is_signed<char>                  { static constexpr bool value = CHAR_MIN < 0;   };
-template <> struct hb_is_signed<signed char>           { static constexpr bool value = true;           };
-template <> struct hb_is_signed<unsigned char>         { static constexpr bool value = false;          };
-template <> struct hb_is_signed<signed short>          { static constexpr bool value = true;           };
-template <> struct hb_is_signed<unsigned short>                { static constexpr bool value = false;          };
-template <> struct hb_is_signed<signed int>            { static constexpr bool value = true;           };
-template <> struct hb_is_signed<unsigned int>          { static constexpr bool value = false;          };
-template <> struct hb_is_signed<signed long>           { static constexpr bool value = true;           };
-template <> struct hb_is_signed<unsigned long>         { static constexpr bool value = false;          };
-template <> struct hb_is_signed<signed long long>      { static constexpr bool value = true;           };
-template <> struct hb_is_signed<unsigned long long>    { static constexpr bool value = false;          };
-template <> struct hb_is_signed<float>                 { static constexpr bool value = true;           };
-template <> struct hb_is_signed<double>                        { static constexpr bool value = true;           };
-template <> struct hb_is_signed<long double>           { static constexpr bool value = true;           };
+#define hb_is_arithmetic(T) hb_is_arithmetic<T>::value
+
+
+template <typename T>
+using hb_is_signed = hb_conditional<hb_is_arithmetic (T),
+                                   hb_bool_constant<(T) -1 < (T) 0>,
+                                   hb_false_type>;
 #define hb_is_signed(T) hb_is_signed<T>::value
+template <typename T>
+using hb_is_unsigned = hb_conditional<hb_is_arithmetic (T),
+                                     hb_bool_constant<(T) 0 < (T) -1>,
+                                     hb_false_type>;
+#define hb_is_unsigned(T) hb_is_unsigned<T>::value
 
 template <typename T> struct hb_int_min;
 template <> struct hb_int_min<char>                    { static constexpr char                 value = CHAR_MIN;       };