text: /*
   * Copyright (c) 2010-2017 OTClient <https://github.com/edubart/otclient>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #ifndef STDEXT_SHARED_PTR_H
  #define STDEXT_SHARED_PTR_H
  
  #include "types.h"
  #include "dumper.h"
  #include <type_traits>
  #include <functional>
  #include <cassert>
  #include <ostream>
  
  #ifdef THREAD_SAFE
  #include <atomic>
  #endif
  
  namespace stdext {
  
  template<class T>
  class shared_ptr;
  
  template<class T>
  class weak_ptr;
  
  template<class T>
  class shared_base
  {
  public:
      shared_base(T* p) : refs(1), weaks(0), px(p) { }
      ~shared_base() { }
  
      void add_ref() { ++refs; }
      void dec_ref() {
          if(--refs == 0) {
              delete px;
              px = nullptr;
              if(weaks == 0)
                  delete this;
          }
      }
  
      void add_weak_ref() { ++weaks; }
      void dec_weak_ref() {
          if(--weaks == 0 && refs == 0)
              delete this;
      }
  
      void set(T *p) {
          T* tmp = px;
          px = p;
          if(tmp)
              delete tmp;
      }
      T *get() { return px; }
  
      refcount_t ref_count() { return refs; }
      refcount_t weak_count() { return weaks; }
      bool expired() { return refs == 0; }
  
  private:
  #ifdef THREAD_SAFE
      std::atomic<refcount_t> refs;
      std::atomic<refcount_t> weaks;
      std::atomic<T*> px;
  #else
      refcount_t refs;
      refcount_t weaks;
      T* px;
  #endif
  };
  
  template<class T>
  class shared_ptr
  {
  public:
      typedef T element_type;
  
      shared_ptr() : base(nullptr) { }
      shared_ptr(T* p) { if(p != nullptr) base = new shared_base<T>(p); else base = nullptr; }
      shared_ptr(shared_ptr const& rhs): base(rhs.base) { if(base != nullptr) base->add_ref(); }
      template<class U>
      shared_ptr(shared_ptr<U> const& rhs, typename std::is_convertible<U,T>::type* = nullptr) : base(rhs.base) { if(base != nullptr) base->add_ref(); }
      ~shared_ptr() { if(base != nullptr) base->dec_ref(); }
  
      void reset() { shared_ptr().swap(*this); }
      void reset(T* rhs) { shared_ptr(rhs).swap(*this); }
      void swap(shared_ptr& rhs) { std::swap(base, rhs.base); }
  
      void set(T* p) { assert(p != nullptr); base->set(p); }
      T* get() const { return base ? base->get() : nullptr; }
  
      refcount_t use_count() const { return base ? base->ref_count() : 0; }
      refcount_t weak_count() const { return base ? base->weak_count() : 0; }
      bool is_unique() const { return use_count() == 1; }
  
      T& operator*() const { assert(base != nullptr); return *base->get(); }
      T* operator->() const { assert(base != nullptr); return base->get(); }
  
      template<class U>
      shared_ptr& operator=(shared_ptr<U> const& rhs) { shared_ptr(rhs).swap(*this); return *this; }
      shared_ptr& operator=(shared_ptr const& rhs) { shared_ptr(rhs).swap(*this); return *this; }
      shared_ptr& operator=(T* rhs) { shared_ptr(rhs).swap(*this); return *this; }
  
      // implicit conversion to bool
      typedef shared_base<T>* shared_ptr::*unspecified_bool_type;
      operator unspecified_bool_type() const { return base == nullptr ? nullptr : &shared_ptr::base; }
      bool operator!() const { return base == nullptr; }
  
      // std::move support
      shared_ptr(shared_ptr&& rhs): base(rhs.base) { rhs.base = nullptr; }
      shared_ptr& operator=(shared_ptr&& rhs) { shared_ptr(static_cast<shared_ptr&&>(rhs)).swap(*this); return *this; }
  
  private:
      shared_ptr(shared_base<T> *base) {
          if(base && !base->expired()) {
              base->add_ref();
              this->base = base;
          } else
              base = nullptr;
      }
      shared_base<T> *base;
  
      friend class weak_ptr<T>;
  };
  
  template<class T>
  class weak_ptr {
  public:
      typedef T element_type;
  
      weak_ptr() : base(nullptr) { }
      weak_ptr(shared_ptr<T> const& rhs): base(rhs.base) { if(base != nullptr) base->add_weak_ref(); }
      template<class U>
      weak_ptr(shared_ptr<U> const& rhs, typename std::is_convertible<U,T>::type* = nullptr) : base(rhs.base) { if(base != nullptr) base->add_weak_ref(); }
      weak_ptr(weak_ptr<T> const& rhs): base(rhs.base) { if(base != nullptr) base->add_weak_ref(); }
      template<class U>
      weak_ptr(weak_ptr<U> const& rhs, typename std::is_convertible<U,T>::type* = nullptr) : base(rhs.base) { if(base != nullptr) base->add_weak_ref(); }
      ~weak_ptr() { if(base != nullptr) base->dec_weak_ref(); }
  
      void reset() { weak_ptr().swap(*this); }
      void swap(weak_ptr& rhs) { std::swap(base, rhs.base); }
  
      T* get() const { return base ? base->get() : nullptr; }
      refcount_t use_count() const { return base ? base->ref_count() : 0; }
      refcount_t weak_count() const { return base ? base->weak_count() : 0; }
      bool expired() const { return base ? base->expired() : false; }
      shared_ptr<T> lock() { return shared_ptr<T>(base); }
  
      weak_ptr& operator=(weak_ptr const& rhs) { weak_ptr(rhs).swap(*this); return *this; }
      template<class U>
      weak_ptr& operator=(shared_ptr<U> const& rhs) { weak_ptr(rhs).swap(*this); return *this; }
      template<class U>
      weak_ptr& operator=(weak_ptr<T> const& rhs) { weak_ptr(rhs).swap(*this); return *this; }
  
      // implicit conversion to bool
      typedef shared_base<T>* weak_ptr::*unspecified_bool_type;
      operator unspecified_bool_type() const { return base == nullptr ? nullptr : &weak_ptr::base; }
      bool operator!() const { return !expired(); }
  
      // std::move support
      weak_ptr(weak_ptr&& rhs): base(rhs.base) { rhs.base = nullptr; }
      weak_ptr& operator=(weak_ptr&& rhs) { weak_ptr(static_cast<weak_ptr&&>(rhs)).swap(*this); return *this; }
  
  private:
      shared_base<T> *base;
  };
  
  template<class T, class U> bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) { return a.get() == b.get(); }
  template<class T, class U> bool operator==(weak_ptr<T> const& a, weak_ptr<U> const& b) { return a.get() == b.get(); }
  template<class T, class U> bool operator==(shared_ptr<T> const& a, weak_ptr<U> const& b) { return a.get() == b.get(); }
  template<class T, class U> bool operator==(weak_ptr<T> const& a, shared_ptr<U> const& b) { return a.get() == b.get(); }
  template<class T, class U> bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) { return a.get() != b.get(); }
  template<class T, class U> bool operator!=(weak_ptr<T> const& a, weak_ptr<U> const& b) { return a.get() != b.get(); }
  template<class T, class U> bool operator!=(shared_ptr<T> const& a, weak_ptr<U> const& b) { return a.get() != b.get(); }
  template<class T, class U> bool operator!=(weak_ptr<T> const& a, shared_ptr<U> const& b) { return a.get() != b.get(); }
  template<class T, class U> bool operator==(shared_ptr<T> const& a, U* b) { return a.get() == b; }
  template<class T, class U> bool operator==(weak_ptr<T> const& a, U* b) { return a.get() == b; }
  template<class T, class U> bool operator!=(shared_ptr<T> const& a, U* b) { return a.get() != b; }
  template<class T, class U> bool operator!=(weak_ptr<T> const& a, U* b) { return a.get() != b; }
  template<class T, class U> bool operator==(T * a, shared_ptr<U> const& b) { return a == b.get(); }
  template<class T, class U> bool operator==(T * a, weak_ptr<U> const& b) { return a == b.get(); }
  template<class T, class U> bool operator!=(T * a, shared_ptr<U> const& b) { return a != b.get(); }
  template<class T, class U> bool operator!=(T * a, weak_ptr<U> const& b) { return a != b.get(); }
  template<class T> bool operator<(shared_ptr<T> const& a, shared_ptr<T> const& b) { return std::less<T*>()(a.get(), b.get()); }
  template<class T> bool operator<(weak_ptr<T> const& a, weak_ptr<T> const& b) { return std::less<T*>()(a.get(), b.get()); }
  
  template<class T> T* get_pointer(shared_ptr<T> const& p) { return p.get(); }
  template<class T> T* get_pointer(weak_ptr<T> const& p) { return p.get(); }
  template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const& p) { return static_cast<T*>(p.get()); }
  template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const& p) { return const_cast<T*>(p.get()); }
  template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& p) { return dynamic_cast<T*>(p.get()); }
  template<class T, typename... Args> stdext::shared_ptr<T> make_shared(Args... args) { return stdext::shared_ptr<T>(new T(args...)); }
  
  // operator<< support
  template<class E, class T, class Y> std::basic_ostream<E, T>& operator<<(std::basic_ostream<E, T>& os, shared_ptr<Y> const& p) { os << p.get(); return os; }
  template<class E, class T, class Y> std::basic_ostream<E, T>& operator<<(std::basic_ostream<E, T>& os, weak_ptr<Y> const& p) { os << p.get(); return os; }
  
  }
  
  namespace std {
  
  // hash, for unordered_map support
  template<typename T> struct hash<stdext::shared_ptr<T>> { size_t operator()(const stdext::shared_ptr<T>& p) const { return std::hash<T*>()(p.get()); } };
  template<typename T> struct hash<stdext::weak_ptr<T>> { size_t operator()(const stdext::weak_ptr<T>& p) const { return std::hash<T*>()(p.get()); } };
  
  // swap support
  template<class T> void swap(stdext::shared_ptr<T>& lhs, stdext::shared_ptr<T>& rhs) { lhs.swap(rhs); }
  template<class T> void swap(stdext::weak_ptr<T>& lhs, stdext::weak_ptr<T>& rhs) { lhs.swap(rhs); }
  
  }
  
  #endif
  