xref: /third_party/backends/backend/genesys/static_init.h

/* sane - Scanner Access Now Easy.

   Copyright (C) 2019 Povilas Kanapickas <povilas@radix.lt>

   This file is part of the SANE package.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

#ifndef BACKEND_GENESYS_STATIC_INIT_H
#define BACKEND_GENESYS_STATIC_INIT_H

#include <functional>
#include <memory>

namespace genesys {

void add_function_to_run_at_backend_exit(const std::function<void()>& function);

// calls functions added via add_function_to_run_at_backend_exit() in reverse order of being
// added.
void run_functions_at_backend_exit();

template<class T>
class StaticInit {
public:
    StaticInit() = default;
    StaticInit(const StaticInit&) = delete;
    StaticInit& operator=(const StaticInit&) = delete;

    template<class... Args>
    void init(Args&& ... args)
    {
        ptr_ = std::unique_ptr<T>(new T(std::forward<Args>(args)...));
        add_function_to_run_at_backend_exit([this](){ deinit(); });
    }

    void deinit()
    {
        ptr_.reset();
    }

    const T* operator->() const { return ptr_.get(); }
    T* operator->() { return ptr_.get(); }
    const T& operator*() const { return *ptr_.get(); }
    T& operator*() { return *ptr_.get(); }

private:
    std::unique_ptr<T> ptr_;
};

} // namespace genesys

#endif // BACKEND_GENESYS_STATIC_INIT_H