#ifndef UNIQUE_FD_HH
#define UNIQUE_FD_HH

#include <cstddef>

class unique_fd {
public:
  constexpr unique_fd() noexcept
    : fd_(-1) {}
  constexpr unique_fd(std::nullptr_t) noexcept
    : fd_(-1) {}
  explicit unique_fd(int fd) noexcept
    : fd_(fd) {}
  unique_fd(unique_fd&& fd) noexcept
    : fd_(fd.release()) {}

  ~unique_fd() { reset(); }

  unique_fd& operator=(unique_fd&& fd) noexcept {
    reset(fd.release());
    return *this;
  }
  unique_fd& operator=(std::nullptr_t) noexcept {
    reset();
    return *this;
  }

  int get() const noexcept { return fd_; }
  int operator*() const { return get(); }

  explicit operator bool() const noexcept { return fd_ >= 0; }

  int release() noexcept {
    int ret = fd_;
    fd_ = -1;
    return ret;
  }

  void reset(int fd = -1);

private:
  unique_fd(unique_fd const&) = delete;
  unique_fd& operator=(unique_fd const&) = delete;

  int fd_;
};

#endif  // UNIQUE_FD_HH