initial commit, 4.5 stable

thirdparty/harfbuzz/src/hb-cplusplus.hh

@@ -0,0 +1,220 @@
+/*
+ * Copyright © 2022 Behdad Esfahbod
+ *
+ *  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.
+ */
+
+#ifndef HB_CPLUSPLUS_HH
+#define HB_CPLUSPLUS_HH
+
+#include "hb.h"
+
+#ifdef __cplusplus
+
+#include <functional>
+#include <utility>
+
+#if 0
+#if !(__cplusplus >= 201103L)
+#error "HarfBuzz C++ helpers require C++11"
+#endif
+#endif
+
+namespace hb {
+
+
+template <typename T>
+struct vtable;
+
+template <typename T>
+struct shared_ptr
+{
+  using element_type = T;
+
+  using v = vtable<T>;
+
+  explicit shared_ptr (T *p = nullptr) : p (p) {}
+  shared_ptr (const shared_ptr &o) : p (v::reference (o.p)) {}
+  shared_ptr (shared_ptr &&o)  noexcept : p (o.p) { o.p = nullptr; }
+  shared_ptr& operator = (const shared_ptr &o) { if (p != o.p) { destroy (); p = o.p; reference (); } return *this; }
+  shared_ptr& operator = (shared_ptr &&o)  noexcept { v::destroy (p); p = o.p; o.p = nullptr; return *this; }
+  ~shared_ptr () { v::destroy (p); p = nullptr; }
+
+  T* get() const { return p; }
+
+  void swap (shared_ptr &o)  noexcept { std::swap (p, o.p); }
+  friend void swap (shared_ptr &a, shared_ptr &b)  noexcept { std::swap (a.p, b.p); }
+
+  operator T * () const { return p; }
+  T& operator * () const { return *get (); }
+  T* operator -> () const { return get (); }
+  operator bool () const { return p; }
+  bool operator == (const shared_ptr &o) const { return p == o.p; }
+  bool operator != (const shared_ptr &o) const { return p != o.p; }
+
+  static T* get_empty() { return v::get_empty (); }
+  T* reference() { return v::reference (p); }
+  void destroy() { v::destroy (p); }
+  void set_user_data (hb_user_data_key_t *key,
+		      void *value,
+		      hb_destroy_func_t destroy,
+		      hb_bool_t replace) { v::set_user_data (p, key, value, destroy, replace); } 
+  void * get_user_data (hb_user_data_key_t *key) { return v::get_user_data (p, key); }
+
+  private:
+  T *p;
+};
+
+template<typename T> struct is_shared_ptr : std::false_type {};
+template<typename T> struct is_shared_ptr<shared_ptr<T>> : std::true_type {};
+
+template <typename T>
+struct unique_ptr
+{
+  using element_type = T;
+
+  using v = vtable<T>;
+
+  explicit unique_ptr (T *p = nullptr) : p (p) {}
+  unique_ptr (const unique_ptr &o) = delete;
+  unique_ptr (unique_ptr &&o)  noexcept : p (o.p) { o.p = nullptr; }
+  unique_ptr& operator = (const unique_ptr &o) = delete;
+  unique_ptr& operator = (unique_ptr &&o)  noexcept { v::destroy (p); p = o.p; o.p = nullptr; return *this; }
+  ~unique_ptr () { v::destroy (p); p = nullptr; }
+
+  T* get() const { return p; }
+  T* release () { T* v = p; p = nullptr; return v; }
+
+  void swap (unique_ptr &o)  noexcept { std::swap (p, o.p); }
+  friend void swap (unique_ptr &a, unique_ptr &b)  noexcept { std::swap (a.p, b.p); }
+
+  operator T * () const { return p; }
+  T& operator * () const { return *get (); }
+  T* operator -> () const { return get (); }
+  operator bool () { return p; }
+
+  private:
+  T *p;
+};
+
+template<typename T> struct is_unique_ptr : std::false_type {};
+template<typename T> struct is_unique_ptr<unique_ptr<T>> : std::true_type {};
+
+template <typename T,
+	  T * (*_get_empty) (void),
+	  T * (*_reference) (T *),
+	  void (*_destroy) (T *),
+	  hb_bool_t (*_set_user_data) (T *,
+				       hb_user_data_key_t *,
+				       void *,
+				       hb_destroy_func_t,
+				       hb_bool_t),
+	  void * (*_get_user_data) (const T *,
+				    hb_user_data_key_t *)>
+struct vtable_t
+{
+  static constexpr auto get_empty = _get_empty;
+  static constexpr auto reference = _reference;
+  static constexpr auto destroy = _destroy;
+  static constexpr auto set_user_data = _set_user_data;
+  static constexpr auto get_user_data = _get_user_data;
+};
+
+#define HB_DEFINE_VTABLE(name) \
+	template<> \
+	struct vtable<hb_##name##_t> \
+	     : vtable_t<hb_##name##_t, \
+			&hb_##name##_get_empty, \
+			&hb_##name##_reference, \
+			&hb_##name##_destroy, \
+			&hb_##name##_set_user_data, \
+			&hb_##name##_get_user_data> {}
+
+HB_DEFINE_VTABLE (buffer);
+HB_DEFINE_VTABLE (blob);
+HB_DEFINE_VTABLE (face);
+HB_DEFINE_VTABLE (font);
+HB_DEFINE_VTABLE (font_funcs);
+HB_DEFINE_VTABLE (map);
+HB_DEFINE_VTABLE (set);
+HB_DEFINE_VTABLE (shape_plan);
+HB_DEFINE_VTABLE (unicode_funcs);
+HB_DEFINE_VTABLE (draw_funcs);
+HB_DEFINE_VTABLE (paint_funcs);
+
+#undef HB_DEFINE_VTABLE
+
+
+#ifdef HB_SUBSET_H
+
+#define HB_DEFINE_VTABLE(name) \
+	template<> \
+	struct vtable<hb_##name##_t> \
+	     : vtable_t<hb_##name##_t, \
+			nullptr, \
+			&hb_##name##_reference, \
+			&hb_##name##_destroy, \
+			&hb_##name##_set_user_data, \
+			&hb_##name##_get_user_data> {}
+
+
+HB_DEFINE_VTABLE (subset_input);
+HB_DEFINE_VTABLE (subset_plan);
+
+#undef HB_DEFINE_VTABLE
+
+#endif
+
+
+} // namespace hb
+
+/* Workaround for GCC < 7, see:
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480
+ * https://stackoverflow.com/a/25594741 */
+namespace std {
+
+
+template<typename T>
+struct hash<hb::shared_ptr<T>>
+{
+    std::size_t operator()(const hb::shared_ptr<T>& v) const noexcept
+    {
+        std::size_t h = std::hash<decltype (v.get ())>{}(v.get ());
+        return h;
+    }
+};
+
+template<typename T>
+struct hash<hb::unique_ptr<T>>
+{
+    std::size_t operator()(const hb::unique_ptr<T>& v) const noexcept
+    {
+        std::size_t h = std::hash<decltype (v.get ())>{}(v.get ());
+        return h;
+    }
+};
+
+
+} // namespace std
+
+#endif /* __cplusplus */
+
+#endif /* HB_CPLUSPLUS_HH */