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Diffstat (limited to 'Build/source/libs/harfbuzz/harfbuzz-src/src/hb-meta.hh')
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1 files changed, 400 insertions, 0 deletions
diff --git a/Build/source/libs/harfbuzz/harfbuzz-src/src/hb-meta.hh b/Build/source/libs/harfbuzz/harfbuzz-src/src/hb-meta.hh new file mode 100644 index 00000000000..df8ebd17503 --- /dev/null +++ b/Build/source/libs/harfbuzz/harfbuzz-src/src/hb-meta.hh @@ -0,0 +1,400 @@ +/* + * Copyright © 2018 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#ifndef HB_META_HH +#define HB_META_HH + +#include "hb.hh" + + +/* + * C++ template meta-programming & fundamentals used with them. + */ + +/* Void! For when we need a expression-type of void. */ +struct hb_empty_t {}; + +/* https://en.cppreference.com/w/cpp/types/void_t */ +template<typename... Ts> struct _hb_void_t { typedef void type; }; +template<typename... Ts> using hb_void_t = typename _hb_void_t<Ts...>::type; + +template<typename Head, typename... Ts> struct _hb_head_t { typedef Head type; }; +template<typename... Ts> using hb_head_t = typename _hb_head_t<Ts...>::type; + +template <typename T, T v> struct hb_integral_constant { static constexpr T value = v; }; +template <bool b> using hb_bool_constant = hb_integral_constant<bool, b>; +using hb_true_type = hb_bool_constant<true>; +using hb_false_type = hb_bool_constant<false>; + + +/* Basic type SFINAE. */ + +template <bool B, typename T = void> struct hb_enable_if {}; +template <typename T> struct hb_enable_if<true, T> { typedef T type; }; +#define hb_enable_if(Cond) typename hb_enable_if<(Cond)>::type* = nullptr +/* Concepts/Requires alias: */ +#define hb_requires(Cond) hb_enable_if((Cond)) + +template <typename T, typename T2> struct hb_is_same : hb_false_type {}; +template <typename T> struct hb_is_same<T, T> : hb_true_type {}; +#define hb_is_same(T, T2) hb_is_same<T, T2>::value + +/* Function overloading SFINAE and priority. */ + +#define HB_RETURN(Ret, E) -> hb_head_t<Ret, decltype ((E))> { return (E); } +#define HB_AUTO_RETURN(E) -> decltype ((E)) { return (E); } +#define HB_VOID_RETURN(E) -> hb_void_t<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 + + +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 +{ + template <typename T> + T* operator () (T& arg) const + { +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wcast-align" + /* https://en.cppreference.com/w/cpp/memory/addressof */ + return reinterpret_cast<T*> ( + &const_cast<char&> ( + reinterpret_cast<const volatile char&> (arg))); +#pragma GCC diagnostic pop + } +} +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 : 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 : 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>; +template <typename T> using hb_add_lvalue_reference = decltype (_hb_try_add_lvalue_reference<T> (hb_prioritize)); +template <typename T> auto _hb_try_add_rvalue_reference (hb_priority<1>) -> hb_type_identity<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 : 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>; +template <typename T> using hb_add_pointer = decltype (_hb_try_add_pointer<T> (hb_prioritize)); +#define hb_is_pointer(T) hb_match_pointer<T>::value + + +/* TODO Add feature-parity to std::decay. */ +template <typename T> using hb_decay = hb_remove_const<hb_remove_reference<T>>; + + +template<bool B, class T, class F> +struct _hb_conditional { typedef T type; }; +template<class T, class F> +struct _hb_conditional<false, T, F> { typedef F type; }; +template<bool B, class T, class F> +using hb_conditional = typename _hb_conditional<B, T, F>::type; + + +template <typename From, typename To> +struct hb_is_convertible +{ + private: + static constexpr bool from_void = hb_is_same (void, hb_decay<From>); + static constexpr bool to_void = hb_is_same (void, hb_decay<To> ); + static constexpr bool either_void = from_void || to_void; + static constexpr bool both_void = from_void && to_void; + + static hb_true_type impl2 (hb_conditional<to_void, int, To>); + + template <typename T> + static auto impl (hb_priority<1>) -> decltype (impl2 (hb_declval (T))); + template <typename T> + static hb_false_type impl (hb_priority<0>); + public: + static constexpr bool value = both_void || + (!either_void && + decltype (impl<hb_conditional<from_void, int, From>> (hb_prioritize))::value); +}; +#define hb_is_convertible(From,To) hb_is_convertible<From, To>::value + +template <typename Base, typename Derived> +using hb_is_base_of = hb_is_convertible<hb_decay<Derived> *, hb_decay<Base> *>; +#define hb_is_base_of(Base,Derived) hb_is_base_of<Base, Derived>::value + +template <typename From, typename To> +using hb_is_cr_convertible = hb_bool_constant< + 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 */ + +template <typename T> +static hb_remove_reference<T>&& hb_move (T&& t) { return (hb_remove_reference<T>&&) (t); } + +template <typename T> +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 (hb_forward<T> (v)) + + template <typename T> auto + operator () (T *v) const HB_AUTO_RETURN (*v) +} +HB_FUNCOBJ (hb_deref); + +struct +{ + template <typename T> auto + operator () (T&& v) const HB_AUTO_RETURN (hb_forward<T> (v)) + + template <typename T> auto + operator () (T& v) const HB_AUTO_RETURN (hb_addressof (v)) +} +HB_FUNCOBJ (hb_ref); + +template <typename T> +struct hb_reference_wrapper +{ + hb_reference_wrapper (T v) : v (v) {} + bool operator == (const hb_reference_wrapper& o) const { return v == o.v; } + bool operator != (const hb_reference_wrapper& o) const { return v != o.v; } + operator T () const { return v; } + T get () const { return v; } + T v; +}; +template <typename T> +struct hb_reference_wrapper<T&> +{ + hb_reference_wrapper (T& v) : v (hb_addressof (v)) {} + bool operator == (const hb_reference_wrapper& o) const { return v == o.v; } + bool operator != (const hb_reference_wrapper& o) const { return v != o.v; } + operator T& () const { return *v; } + T& get () const { return *v; } + T* v; +}; + + +template <typename T> +using hb_is_integral = hb_bool_constant< + hb_is_same (hb_decay<T>, char) || + hb_is_same (hb_decay<T>, signed char) || + hb_is_same (hb_decay<T>, unsigned char) || + hb_is_same (hb_decay<T>, signed int) || + hb_is_same (hb_decay<T>, unsigned int) || + hb_is_same (hb_decay<T>, signed short) || + hb_is_same (hb_decay<T>, unsigned short) || + hb_is_same (hb_decay<T>, signed long) || + hb_is_same (hb_decay<T>, unsigned long) || + hb_is_same (hb_decay<T>, signed long long) || + hb_is_same (hb_decay<T>, unsigned long long) || + false +>; +#define hb_is_integral(T) hb_is_integral<T>::value +template <typename T> +using hb_is_floating_point = hb_bool_constant< + hb_is_same (hb_decay<T>, float) || + hb_is_same (hb_decay<T>, double) || + hb_is_same (hb_decay<T>, long double) || + false +>; +#define hb_is_floating_point(T) hb_is_floating_point<T>::value +template <typename T> +using hb_is_arithmetic = hb_bool_constant< + hb_is_integral (T) || + hb_is_floating_point (T) || + false +>; +#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> : hb_integral_constant<char, CHAR_MIN> {}; +template <> struct hb_int_min<signed char> : hb_integral_constant<signed char, SCHAR_MIN> {}; +template <> struct hb_int_min<unsigned char> : hb_integral_constant<unsigned char, 0> {}; +template <> struct hb_int_min<signed short> : hb_integral_constant<signed short, SHRT_MIN> {}; +template <> struct hb_int_min<unsigned short> : hb_integral_constant<unsigned short, 0> {}; +template <> struct hb_int_min<signed int> : hb_integral_constant<signed int, INT_MIN> {}; +template <> struct hb_int_min<unsigned int> : hb_integral_constant<unsigned int, 0> {}; +template <> struct hb_int_min<signed long> : hb_integral_constant<signed long, LONG_MIN> {}; +template <> struct hb_int_min<unsigned long> : hb_integral_constant<unsigned long, 0> {}; +template <> struct hb_int_min<signed long long> : hb_integral_constant<signed long long, LLONG_MIN> {}; +template <> struct hb_int_min<unsigned long long> : hb_integral_constant<unsigned long long, 0> {}; +#define hb_int_min(T) hb_int_min<T>::value +template <typename T> struct hb_int_max; +template <> struct hb_int_max<char> : hb_integral_constant<char, CHAR_MAX> {}; +template <> struct hb_int_max<signed char> : hb_integral_constant<signed char, SCHAR_MAX> {}; +template <> struct hb_int_max<unsigned char> : hb_integral_constant<unsigned char, UCHAR_MAX> {}; +template <> struct hb_int_max<signed short> : hb_integral_constant<signed short, SHRT_MAX> {}; +template <> struct hb_int_max<unsigned short> : hb_integral_constant<unsigned short, USHRT_MAX> {}; +template <> struct hb_int_max<signed int> : hb_integral_constant<signed int, INT_MAX> {}; +template <> struct hb_int_max<unsigned int> : hb_integral_constant<unsigned int, UINT_MAX> {}; +template <> struct hb_int_max<signed long> : hb_integral_constant<signed long, LONG_MAX> {}; +template <> struct hb_int_max<unsigned long> : hb_integral_constant<unsigned long, ULONG_MAX> {}; +template <> struct hb_int_max<signed long long> : hb_integral_constant<signed long long, LLONG_MAX> {}; +template <> struct hb_int_max<unsigned long long> : hb_integral_constant<unsigned long long, ULLONG_MAX> {}; +#define hb_int_max(T) hb_int_max<T>::value + + + +template <typename T, typename> +struct _hb_is_destructible : hb_false_type {}; +template <typename T> +struct _hb_is_destructible<T, hb_void_t<decltype (hb_declval (T).~T ())>> : hb_true_type {}; +template <typename T> +using hb_is_destructible = _hb_is_destructible<T, void>; +#define hb_is_destructible(T) hb_is_destructible<T>::value + +template <typename T, typename, typename ...Ts> +struct _hb_is_constructible : hb_false_type {}; +template <typename T, typename ...Ts> +struct _hb_is_constructible<T, hb_void_t<decltype (T (hb_declval (Ts)...))>, Ts...> : hb_true_type {}; +template <typename T, typename ...Ts> +using hb_is_constructible = _hb_is_constructible<T, void, Ts...>; +#define hb_is_constructible(...) hb_is_constructible<__VA_ARGS__>::value + +template <typename T> +using hb_is_default_constructible = hb_is_constructible<T>; +#define hb_is_default_constructible(T) hb_is_default_constructible<T>::value + +template <typename T> +using hb_is_copy_constructible = hb_is_constructible<T, hb_add_lvalue_reference<hb_add_const<T>>>; +#define hb_is_copy_constructible(T) hb_is_copy_constructible<T>::value + +template <typename T> +using hb_is_move_constructible = hb_is_constructible<T, hb_add_rvalue_reference<hb_add_const<T>>>; +#define hb_is_move_constructible(T) hb_is_move_constructible<T>::value + +template <typename T, typename U, typename> +struct _hb_is_assignable : hb_false_type {}; +template <typename T, typename U> +struct _hb_is_assignable<T, U, hb_void_t<decltype (hb_declval (T) = hb_declval (U))>> : hb_true_type {}; +template <typename T, typename U> +using hb_is_assignable = _hb_is_assignable<T, U, void>; +#define hb_is_assignable(T,U) hb_is_assignable<T, U>::value + +template <typename T> +using hb_is_copy_assignable = hb_is_assignable<hb_add_lvalue_reference<T>, + hb_add_lvalue_reference<hb_add_const<T>>>; +#define hb_is_copy_assignable(T) hb_is_copy_assignable<T>::value + +template <typename T> +using hb_is_move_assignable = hb_is_assignable<hb_add_lvalue_reference<T>, + hb_add_rvalue_reference<T>>; +#define hb_is_move_assignable(T) hb_is_move_assignable<T>::value + +/* Trivial versions. */ + +template <typename T> union hb_trivial { T value; }; + +/* Don't know how to do the following. */ +template <typename T> +using hb_is_trivially_destructible= hb_is_destructible<hb_trivial<T>>; +#define hb_is_trivially_destructible(T) hb_is_trivially_destructible<T>::value + +/* Don't know how to do the following. */ +//template <typename T, typename ...Ts> +//using hb_is_trivially_constructible= hb_is_constructible<hb_trivial<T>, hb_trivial<Ts>...>; +//#define hb_is_trivially_constructible(...) hb_is_trivially_constructible<__VA_ARGS__>::value + +template <typename T> +using hb_is_trivially_default_constructible= hb_is_default_constructible<hb_trivial<T>>; +#define hb_is_trivially_default_constructible(T) hb_is_trivially_default_constructible<T>::value + +template <typename T> +using hb_is_trivially_copy_constructible= hb_is_copy_constructible<hb_trivial<T>>; +#define hb_is_trivially_copy_constructible(T) hb_is_trivially_copy_constructible<T>::value + +template <typename T> +using hb_is_trivially_move_constructible= hb_is_move_constructible<hb_trivial<T>>; +#define hb_is_trivially_move_constructible(T) hb_is_trivially_move_constructible<T>::value + +/* Don't know how to do the following. */ +//template <typename T, typename U> +//using hb_is_trivially_assignable= hb_is_assignable<hb_trivial<T>, hb_trivial<U>>; +//#define hb_is_trivially_assignable(T,U) hb_is_trivially_assignable<T, U>::value + +template <typename T> +using hb_is_trivially_copy_assignable= hb_is_copy_assignable<hb_trivial<T>>; +#define hb_is_trivially_copy_assignable(T) hb_is_trivially_copy_assignable<T>::value + +template <typename T> +using hb_is_trivially_move_assignable= hb_is_move_assignable<hb_trivial<T>>; +#define hb_is_trivially_move_assignable(T) hb_is_trivially_move_assignable<T>::value + +template <typename T> +using hb_is_trivially_copyable= hb_bool_constant< + hb_is_trivially_destructible (T) && + (!hb_is_move_assignable (T) || hb_is_trivially_move_assignable (T)) && + (!hb_is_move_constructible (T) || hb_is_trivially_move_constructible (T)) && + (!hb_is_copy_assignable (T) || hb_is_trivially_copy_assignable (T)) && + (!hb_is_copy_constructible (T) || hb_is_trivially_copy_constructible (T)) && + true +>; +#define hb_is_trivially_copyable(T) hb_is_trivially_copyable<T>::value + +template <typename T> +using hb_is_trivial= hb_bool_constant< + hb_is_trivially_copyable (T) && + hb_is_trivially_default_constructible (T) +>; +#define hb_is_trivial(T) hb_is_trivial<T>::value + + +#endif /* HB_META_HH */ |