UniqueResource.h

/*
 * Copyright (c) 2026, Pedigree Developers
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted.
 */
 
#ifndef PEDIGREE_KERNEL_UTILITIES_UNIQUERESOURCE_H
#define PEDIGREE_KERNEL_UTILITIES_UNIQUERESOURCE_H
#include "pedigree/kernel/compiler.h"
 
#include <config.h>
 
template <class T, class Releaser>
class UniqueResource {
 public:
  UniqueResource() : m_Resource(nullptr) {}
 
  UniqueResource(UniqueResource&& other) noexcept : m_Resource(other.release()) {}
 
  ~UniqueResource() {
    reset();
  }
 
  UniqueResource& operator=(UniqueResource&& other) noexcept {
    if (this != &other) {
      reset();
      m_Resource = other.release();
    }
    return *this;
  }
 
  MUST_USE_RESULT static UniqueResource adopt(T* resource) {
    return UniqueResource(resource);
  }
 
  T* get() const {
    return m_Resource;
  }
 
  T* operator->() const {
    return m_Resource;
  }
 
  T& operator*() const {
    return *m_Resource;
  }
 
  explicit operator bool() const {
    return m_Resource != nullptr;
  }
 
  MUST_USE_RESULT T* release() noexcept {
    T* resource = m_Resource;
    m_Resource = nullptr;
    return resource;
  }
 
  void reset(T* replacement = nullptr) noexcept {
    if (replacement == m_Resource) {
      return;
    }
    T* resource = m_Resource;
    m_Resource = nullptr;
    if (resource) {
      Releaser::release(resource);
    }
    m_Resource = replacement;
  }
 
 private:
  explicit UniqueResource(T* resource) : m_Resource(resource) {}
 
  UniqueResource(const UniqueResource&) = delete;
  UniqueResource& operator=(const UniqueResource&) = delete;
 
  T* m_Resource;
};
 
#endif