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// **************************************************************************
// * This file is part of the zenXML project. It is distributed under the   *
// * Boost Software License: http://www.boost.org/LICENSE_1_0.txt           *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved        *
// **************************************************************************

#ifndef ZEN_SCOPEGUARD_8971632487321434
#define ZEN_SCOPEGUARD_8971632487321434

#include <cassert>

//best of Zen, Loki and C++11

namespace zen
{
//Scope Guard
/*
    zen::ScopeGuard lockAio = zen::makeGuard([&]() { ::CancelIo(hDir); });
		...
	lockAio.dismiss();
*/

//Scope Exit
/*
	ZEN_ON_SCOPE_EXIT(::CloseHandle(hDir));
*/

class ScopeGuardBase
{
public:
    void dismiss() const { dismissed_ = true; }

protected:
    ScopeGuardBase() : dismissed_(false) {}
    ScopeGuardBase(const ScopeGuardBase& other) : dismissed_(other.dismissed_) { other.dismissed_ = true; } //take over responsibility
    ~ScopeGuardBase() {}

    bool isDismissed() const { return dismissed_; }

private:
    ScopeGuardBase& operator=(const ScopeGuardBase&); // = delete;

    mutable bool dismissed_;
};


template <typename F>
class ScopeGuardImpl : public ScopeGuardBase
{
public:
    ScopeGuardImpl(F fun) : fun_(fun) {}

    ~ScopeGuardImpl()
    {
        if (!this->isDismissed())
            try
            {
                fun_();
            }
            catch (...) { assert(false); }
    }

private:
    F fun_;
};

typedef const ScopeGuardBase& ScopeGuard;

template <class F> inline
ScopeGuardImpl<F> makeGuard(F fun) { return ScopeGuardImpl<F>(fun); }
}

#define ZEN_CONCAT_SUB(X, Y) X ## Y
#define ZEN_CONCAT(X, Y) ZEN_CONCAT_SUB(X, Y)

#define ZEN_ON_SCOPE_EXIT(X) zen::ScopeGuard ZEN_CONCAT(dummy, __LINE__) = zen::makeGuard([&]{ X; }); (void)ZEN_CONCAT(dummy, __LINE__);

#endif //ZEN_SCOPEGUARD_8971632487321434
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