use.h

// This file if part of the llir-opt project.
// Licensing information can be found in the LICENSE file.
// (C) 2018 Nandor Licker. All rights reserved.
 
#pragma once
 
#include "core/ref.h"
 
class Use;
class User;
class Value;
 
 
 
class Use final {
public:
  Use() : val_(nullptr), user_(nullptr) {}
  Use(Ref<Value> val, User *user);
  ~Use();
 
  Use(const Use &) = delete;
  Use(Use &&) = delete;
 
  Use &operator = (Ref<Value> val);
 
  Use &operator = (const Use &) = delete;
  Use &operator = (Use &&) = delete;
 
  User *getUser() const { return user_; }
  Use *getNext() const { return next_; }
 
  // Return the underlying value.
  Ref<Value> get() { return val_; }
  // Return the underlying value.
  ConstRef<Value> get() const { return val_; }
 
  // Return the underlying value.
  operator Ref<Value>&() { return val_; }
  // Return the underlying value.
  operator ConstRef<Value>() const { return val_; }
 
  // Return the underlying value.
  Ref<Value> operator*() { return val_; }
  // Return the underlying value.
  ConstRef<Value> operator*() const { return val_; }
  // Point to the underlying value.
  Ref<Value> operator->() { return val_; }
  // Point to the underlying value.
  ConstRef<Value> operator->() const { return val_; }
 
  // Checks if the use points to a value.
  operator bool() const { return val_; }
 
private:
  friend class Value;
  friend class User;
 
  void Remove();
  void Add();
 
  Ref<Value> val_;
  User *user_;
  Use *prev_ = nullptr;
  Use *next_ = nullptr;
};