/**
 * @file utils.hpp
 * @author Gustice
 * @brief Template
 *
 * @copyright Copyright (c) 2024
 */
#pragma once

#include <cassert>
#include <exception>
#include <cstdint>

/**
 * @brief Base for constructs that allow only one concurrently active instance
 *
 * @tparam T
 * @note needs a `T * T::SingleActive<T>::active{};` definition in source
 */
template <typename T>
class SingleActive {
    static bool active;

  public:
    /// @brief Constructor, memorizes if already on instance was successfully build
    SingleActive() {
        if (active) {
            throw "Instance already active";
        }
        assert(active == false && "Constructor my only be run if no instance active");
        active = true;
    }

    /// @brief Destructor, clears memory of existing instance
    ~SingleActive() {
        assert(active == true && "Destructor my only be run on active instance");
        active = false;
    }

    // Disable move and assignment
    SingleActive(SingleActive &other) = delete;
    void operator=(const SingleActive &) = delete;
};