New upstream version 1.0.29upstream/1.0.29

1 files changed, 88 insertions, 0 deletions

diff --git a/backend/genesys/static_init.h b/backend/genesys/static_init.h
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+/* 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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+*/
+
+#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