optional_ref.h

// SPDX-FileCopyrightText: © 2025-2026 Alexandros Theodotou <alex@zrythm.org>
// SPDX-License-Identifier: LicenseRef-ZrythmLicense
 
#pragma once
 
#include <cassert>
#include <functional>
#include <optional>
 
namespace zrythm::utils
{

template <typename T> struct OptionalRef
{
  OptionalRef () = default;
  OptionalRef (std::nullopt_t) { }
  OptionalRef (T &ref) : ref_ (ref) { }
 
  std::optional<std::reference_wrapper<T>> ref_;

  T &operator* ()
  {
    assert (has_value ());
    return ref_->get ();
  }
  const T &operator* () const
  {
    assert (has_value ());
    return ref_->get ();
  }
 
  const T * operator->() const
  {
    assert (has_value ());
    return std::addressof (ref_->get ());
  }
  T * operator->()
  {
    assert (has_value ());
    return std::addressof (ref_->get ());
  }
 
  explicit operator bool () const { return has_value (); }

  bool has_value () const { return ref_.has_value (); }

  T &value ()
  {
    assert (has_value ());
    return ref_->get ();
  }
};
} // namespace zrythm::utils