1/*
2 * Copyright © 2022 Behdad Esfahbod
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 */
24
25#ifndef HB_CPLUSPLUS_HH
26#define HB_CPLUSPLUS_HH
27
28#include "hb.h"
29
30HB_BEGIN_DECLS
31HB_END_DECLS
32
33#ifdef __cplusplus
34
35#include <functional>
36#include <utility>
37
38#if 0
39#if !(__cplusplus >= 201103L)
40#error "HarfBuzz C++ helpers require C++11"
41#endif
42#endif
43
44namespace hb {
45
46
47template <typename T>
48struct vtable;
49
50template <typename T>
51struct shared_ptr
52{
53 using element_type = T;
54
55 using v = vtable<T>;
56
57 explicit shared_ptr (T *p = nullptr) : p (p) {}
58 shared_ptr (const shared_ptr &o) : p (v::reference (o.p)) {}
59 shared_ptr (shared_ptr &&o) : p (o.p) { o.p = nullptr; }
60 shared_ptr& operator = (const shared_ptr &o) { if (p != o.p) { destroy (); p = o.p; reference (); } return *this; }
61 shared_ptr& operator = (shared_ptr &&o) { v::destroy (p); p = o.p; o.p = nullptr; return *this; }
62 ~shared_ptr () { v::destroy (p); p = nullptr; }
63
64 T* get() const { return p; }
65
66 void swap (shared_ptr &o) { std::swap (p, o.p); }
67 friend void swap (shared_ptr &a, shared_ptr &b) { std::swap (a.p, b.p); }
68
69 operator T * () const { return p; }
70 T& operator * () const { return *get (); }
71 T* operator -> () const { return get (); }
72 operator bool () const { return p; }
73 bool operator == (const shared_ptr &o) const { return p == o.p; }
74 bool operator != (const shared_ptr &o) const { return p != o.p; }
75
76 static T* get_empty() { return v::get_empty (); }
77 T* reference() { return v::reference (p); }
78 void destroy() { v::destroy (p); }
79 void set_user_data (hb_user_data_key_t *key,
80 void *value,
81 hb_destroy_func_t destroy,
82 hb_bool_t replace) { v::set_user_data (p, key, value, destroy, replace); }
83 void * get_user_data (hb_user_data_key_t *key) { return v::get_user_data (p, key); }
84
85 private:
86 T *p;
87};
88
89template<typename T> struct is_shared_ptr : std::false_type {};
90template<typename T> struct is_shared_ptr<shared_ptr<T>> : std::true_type {};
91
92template <typename T>
93struct unique_ptr
94{
95 using element_type = T;
96
97 using v = vtable<T>;
98
99 explicit unique_ptr (T *p = nullptr) : p (p) {}
100 unique_ptr (const unique_ptr &o) = delete;
101 unique_ptr (unique_ptr &&o) : p (o.p) { o.p = nullptr; }
102 unique_ptr& operator = (const unique_ptr &o) = delete;
103 unique_ptr& operator = (unique_ptr &&o) { v::destroy (p); p = o.p; o.p = nullptr; return *this; }
104 ~unique_ptr () { v::destroy (p); p = nullptr; }
105
106 T* get() const { return p; }
107 T* release () { T* v = p; p = nullptr; return v; }
108
109 void swap (unique_ptr &o) { std::swap (p, o.p); }
110 friend void swap (unique_ptr &a, unique_ptr &b) { std::swap (a.p, b.p); }
111
112 operator T * () const { return p; }
113 T& operator * () const { return *get (); }
114 T* operator -> () const { return get (); }
115 operator bool () { return p; }
116
117 private:
118 T *p;
119};
120
121template<typename T> struct is_unique_ptr : std::false_type {};
122template<typename T> struct is_unique_ptr<unique_ptr<T>> : std::true_type {};
123
124template <typename T,
125 T * (*_get_empty) (void),
126 T * (*_reference) (T *),
127 void (*_destroy) (T *),
128 hb_bool_t (*_set_user_data) (T *,
129 hb_user_data_key_t *,
130 void *,
131 hb_destroy_func_t,
132 hb_bool_t),
133 void * (*_get_user_data) (const T *,
134 hb_user_data_key_t *)>
135struct vtable_t
136{
137 static constexpr auto get_empty = _get_empty;
138 static constexpr auto reference = _reference;
139 static constexpr auto destroy = _destroy;
140 static constexpr auto set_user_data = _set_user_data;
141 static constexpr auto get_user_data = _get_user_data;
142};
143
144#define HB_DEFINE_VTABLE(name) \
145 template<> \
146 struct vtable<hb_##name##_t> \
147 : vtable_t<hb_##name##_t, \
148 &hb_##name##_get_empty, \
149 &hb_##name##_reference, \
150 &hb_##name##_destroy, \
151 &hb_##name##_set_user_data, \
152 &hb_##name##_get_user_data> {}
153
154HB_DEFINE_VTABLE (buffer);
155HB_DEFINE_VTABLE (blob);
156HB_DEFINE_VTABLE (face);
157HB_DEFINE_VTABLE (font);
158HB_DEFINE_VTABLE (font_funcs);
159HB_DEFINE_VTABLE (map);
160HB_DEFINE_VTABLE (set);
161HB_DEFINE_VTABLE (shape_plan);
162HB_DEFINE_VTABLE (unicode_funcs);
163HB_DEFINE_VTABLE (draw_funcs);
164HB_DEFINE_VTABLE (paint_funcs);
165
166#undef HB_DEFINE_VTABLE
167
168
169#ifdef HB_SUBSET_H
170
171#define HB_DEFINE_VTABLE(name) \
172 template<> \
173 struct vtable<hb_##name##_t> \
174 : vtable_t<hb_##name##_t, \
175 nullptr, \
176 &hb_##name##_reference, \
177 &hb_##name##_destroy, \
178 &hb_##name##_set_user_data, \
179 &hb_##name##_get_user_data> {}
180
181
182HB_DEFINE_VTABLE (subset_input);
183HB_DEFINE_VTABLE (subset_plan);
184
185#undef HB_DEFINE_VTABLE
186
187#endif
188
189
190} // namespace hb
191
192/* Workaround for GCC < 7, see:
193 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480
194 * https://stackoverflow.com/a/25594741 */
195namespace std {
196
197
198template<typename T>
199struct hash<hb::shared_ptr<T>>
200{
201 std::size_t operator()(const hb::shared_ptr<T>& v) const noexcept
202 {
203 std::size_t h = std::hash<decltype (v.get ())>{}(v.get ());
204 return h;
205 }
206};
207
208template<typename T>
209struct hash<hb::unique_ptr<T>>
210{
211 std::size_t operator()(const hb::unique_ptr<T>& v) const noexcept
212 {
213 std::size_t h = std::hash<decltype (v.get ())>{}(v.get ());
214 return h;
215 }
216};
217
218
219} // namespace std
220
221#endif /* __cplusplus */
222
223#endif /* HB_CPLUSPLUS_HH */
224