diff options
Diffstat (limited to 'thirdparty/harfbuzz/src/hb-null.hh')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-null.hh | 55 |
1 files changed, 48 insertions, 7 deletions
diff --git a/thirdparty/harfbuzz/src/hb-null.hh b/thirdparty/harfbuzz/src/hb-null.hh index d09f858cde..0d7f4da79e 100644 --- a/thirdparty/harfbuzz/src/hb-null.hh +++ b/thirdparty/harfbuzz/src/hb-null.hh @@ -37,10 +37,31 @@ /* Global nul-content Null pool. Enlarge as necessary. */ -#define HB_NULL_POOL_SIZE 384 +#define HB_NULL_POOL_SIZE 448 -/* Use SFINAE to sniff whether T has min_size; in which case return T::null_size, - * otherwise return sizeof(T). */ +template <typename T, typename> +struct _hb_has_min_size : hb_false_type {}; +template <typename T> +struct _hb_has_min_size<T, hb_void_t<decltype (T::min_size)>> + : hb_true_type {}; +template <typename T> +using hb_has_min_size = _hb_has_min_size<T, void>; +#define hb_has_min_size(T) hb_has_min_size<T>::value + +template <typename T, typename> +struct _hb_has_null_size : hb_false_type {}; +template <typename T> +struct _hb_has_null_size<T, hb_void_t<decltype (T::null_size)>> + : hb_true_type {}; +template <typename T> +using hb_has_null_size = _hb_has_null_size<T, void>; +#define hb_has_null_size(T) hb_has_null_size<T>::value + +/* Use SFINAE to sniff whether T has min_size; in which case return the larger + * of sizeof(T) and T::null_size, otherwise return sizeof(T). + * + * The main purpose of this is to let structs communicate that they are not nullable, + * by defining min_size but *not* null_size. */ /* The hard way... * https://stackoverflow.com/questions/7776448/sfinae-tried-with-bool-gives-compiler-error-template-argument-tvalue-invol @@ -49,8 +70,9 @@ template <typename T, typename> struct _hb_null_size : hb_integral_constant<unsigned, sizeof (T)> {}; template <typename T> -struct _hb_null_size<T, hb_void_t<decltype (T::min_size)>> : hb_integral_constant<unsigned, T::null_size> {}; - +struct _hb_null_size<T, hb_void_t<decltype (T::min_size)>> + : hb_integral_constant<unsigned, + (sizeof (T) > T::null_size ? sizeof (T) : T::null_size)> {}; template <typename T> using hb_null_size = _hb_null_size<T, void>; #define hb_null_size(T) hb_null_size<T>::value @@ -68,6 +90,14 @@ template <typename T> using hb_static_size = _hb_static_size<T, void>; #define hb_static_size(T) hb_static_size<T>::value +template <typename T, typename> +struct _hb_min_size : hb_integral_constant<unsigned, sizeof (T)> {}; +template <typename T> +struct _hb_min_size<T, hb_void_t<decltype (T::min_size)>> : hb_integral_constant<unsigned, T::min_size> {}; +template <typename T> +using hb_min_size = _hb_min_size<T, void>; +#define hb_min_size(T) hb_min_size<T>::value + /* * Null() @@ -96,7 +126,7 @@ struct NullHelper /* Specializations for arbitrary-content Null objects expressed in bytes. */ #define DECLARE_NULL_NAMESPACE_BYTES(Namespace, Type) \ } /* Close namespace. */ \ - extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::null_size]; \ + extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[hb_null_size (Namespace::Type)]; \ template <> \ struct Null<Namespace::Type> { \ static Namespace::Type const & get_null () { \ @@ -105,8 +135,19 @@ struct NullHelper }; \ namespace Namespace { \ static_assert (true, "") /* Require semicolon after. */ +#define DECLARE_NULL_NAMESPACE_BYTES_TEMPLATE1(Namespace, Type, Size) \ + } /* Close namespace. */ \ + extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[Size]; \ + template <typename Spec> \ + struct Null<Namespace::Type<Spec>> { \ + static Namespace::Type<Spec> const & get_null () { \ + return *reinterpret_cast<const Namespace::Type<Spec> *> (_hb_Null_##Namespace##_##Type); \ + } \ + }; \ + namespace Namespace { \ + static_assert (true, "") /* Require semicolon after. */ #define DEFINE_NULL_NAMESPACE_BYTES(Namespace, Type) \ - const unsigned char _hb_Null_##Namespace##_##Type[Namespace::Type::null_size] + const unsigned char _hb_Null_##Namespace##_##Type[sizeof (_hb_Null_##Namespace##_##Type)] /* Specializations for arbitrary-content Null objects expressed as struct initializer. */ #define DECLARE_NULL_INSTANCE(Type) \ |