lock_helper.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#pragma once

#include <type_traits>

namespace mrpt
{
/** Auxiliary helper structure for mrpt::lockHelper()
 * \ingroup mrpt_core_grp
 */
template <class T>
class LockHelper
{
    using Tnc = std::remove_const_t<T>;

   public:
    LockHelper(const Tnc* l) : l_{const_cast<Tnc*>(l)} { l_->lock(); }
    ~LockHelper()
    {
        if (l_) l_->unlock();
    }

    LockHelper(const LockHelper& o) = delete;
    LockHelper& operator=(const LockHelper& o) = delete;

    LockHelper(LockHelper&& o) : l_{o.l} { o.l = nullptr; }
    LockHelper& operator=(LockHelper&& o)
    {
        l_ = o.l;
        o.l = nullptr;
        return *this;
    }

   private:
    Tnc* l_{nullptr};
};

/** Syntactic sugar to easily create a locker to any kind of std::mutex
 * \ingroup mrpt_core_grp
 */
template <class T>
LockHelper<T> lockHelper(T& t)
{
    return LockHelper<T>(&t);
}
}  // namespace mrpt