pointer.h

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#ifndef __MEOWPP_UTILITY_POINTER_H__
#define __MEOWPP_UTILITY_POINTER_H__

#include <cstddef>
#include <cstdlib>

#include "object.h"

namespace meow {


enum PointerType {
  SINGLE = 0,
  ARRAY = 1
};


template<typename Type>
class Pointer : public Object {
 private:
  struct RealPointer {
    Type* address;

    PointerType type;

    bool auto_delete;

    int counter;

    RealPointer(Type* arg_address,
                PointerType arg_type,
                bool arg_auto_delete,
                int arg_counter) :
        address(arg_address),
        type(arg_type),
        auto_delete(arg_auto_delete),
        counter(arg_counter) {}

    ~RealPointer() {
      if (auto_delete) {
        switch (type) {
        case SINGLE:
          delete address;
          break;
        case ARRAY:
          delete [] address;
          break;
        }
      }
    }
  };

  RealPointer* ptr_;

  void Attach(RealPointer* arg_ptr2) {
    ptr_ = arg_ptr2;
    ptr_->counter += 1;
  }

  void Detach() {
    ptr_->counter -= 1;
    if (ptr_->counter == 0) {
      delete ptr_;
    }
  }
 public:
  Pointer() : Pointer(NULL, SINGLE, false) {}

  Pointer(Pointer const& arg_ptr) {
    Attach(arg_ptr.ptr_);
  }

  Pointer(Type* arg_address, PointerType arg_type, bool arg_auto_delete) :
      ptr_(new RealPointer(arg_address, arg_type, arg_auto_delete, 1)) {}

  ~Pointer() { Detach(); }

  bool auto_delete() const {
    return ptr_->auto_delete;
  }

  Type* address() const {
    return ptr_->address;
  }

  operator Type*() const {
    return address();
  }

  Type* operator->() const {
    return address();
  }

  Pointer& operator=(Pointer const& b) {
    Detach();
    Attach(b.ptr_);
    return *this;
  }

  Object* Copy() const {
    return new Pointer(*this);
  }

  Object* CopyFrom(Object const* another_pointer) {
    (*this) = *dynamic_cast<Pointer const*>(another_pointer);
    return this;
  }

  bool Equals(Object const* another_pointer) {
    return (ptr_->address ==
            dynamic_cast<Pointer const*>(another_pointer)->ptr_->address);
  }

#ifdef MEOWPP_UTILITY_POINTER_TESTING
  friend class PointerTest;
#endif // MEOWPP_UTILLITY_POINTER_TESTING

};

}  // meow

#endif  // __MEOWPP_UTILITY_POINTER_H__