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// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
// **************************************************************************
#ifndef ZEN_SCOPEGUARD_8971632487321434
#define ZEN_SCOPEGUARD_8971632487321434
#include <cassert>
//#include <type_traits> //std::decay
//#include <utility>
//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() { dismissed_ = true; }
protected:
ScopeGuardBase() : dismissed_(false) {}
ScopeGuardBase(ScopeGuardBase&& other) : dismissed_(other.dismissed_) { other.dismiss(); } //take over responsibility
~ScopeGuardBase() {} //[!] protected non-virtual base class destructor
bool isDismissed() const { return dismissed_; }
private:
ScopeGuardBase (const ScopeGuardBase&); // = delete
ScopeGuardBase& operator=(const ScopeGuardBase&); //
bool dismissed_;
};
template <typename F>
class ScopeGuardImpl : public ScopeGuardBase
{
public:
explicit ScopeGuardImpl(const F& fun) : fun_(fun) {}
explicit ScopeGuardImpl(F&& fun) : fun_(std::move(fun)) {}
ScopeGuardImpl(ScopeGuardImpl&& other) : ScopeGuardBase(std::move(other)), fun_(std::move(other.fun_)) {}
~ScopeGuardImpl()
{
if (!this->isDismissed())
try
{
fun_();
}
catch (...) { assert(false); }
}
private:
F fun_;
};
typedef ScopeGuardBase&& ScopeGuard;
template <class F> inline
ScopeGuardImpl<typename std::decay<F>::type> makeGuard(F&& fun) { return ScopeGuardImpl<typename std::decay<F>::type>(std::forward<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) auto ZEN_CONCAT(dummy, __LINE__) = zen::makeGuard([&]{ X; }); (void)ZEN_CONCAT(dummy, __LINE__);
#endif //ZEN_SCOPEGUARD_8971632487321434
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