SCOPE EXIT

#pragma once

// https://www.youtube.com/watch?v=WjTrfoiB0MQ

#include <utility>

template<typename T>
class ScopeGuard final
{
public:

    explicit ScopeGuard(T onExit)
        : ready_(true)
        , onExit_(onExit)
    {
    }

    ScopeGuard(ScopeGuard&& other) noexcept
        : ready_(true)
        , onExit_(other.onExit_)
    {
        other.ready_ = false;
    }

    ~ScopeGuard()
    {
        if (ready_)
        {
            onExit_();
            ready_ = false;
        }
    }

    ScopeGuard() = delete;
    ScopeGuard(ScopeGuard& other) = delete;
    ScopeGuard& operator=(ScopeGuard&& other) = delete;
    ScopeGuard& operator=(const ScopeGuard& other) = delete;

private:

    bool ready_;
    T onExit_;

};

namespace detail
{
    enum class ScopeGuardOnExit {};

    template<typename Function>
    ScopeGuard<Function> operator+(ScopeGuardOnExit, Function&& function)
    {
        return ScopeGuard<Function>(std::forward<Function>(function));
    }
}

#define CONCATENATE_IMPL(s1, s2) s1##s2
#define CONCATENATE(s1, s2) CONCATENATE_IMPL(s1, s2)

#ifdef __COUNTER__
#define ANONYMOUS_VARIABLE(string) CONCATINATE(string, __COUNTER__)
#else
#define ANONYMOUS_VARIABLE(string) CONCATINATE(string, __LINE__)
#endif

#define SCOPE_EXIT auto ANONIMOUS_VARIABLE(SCOPE_EXIT_STATE) = ::detail::ScopeGuardOnExit + (&)[]