scope_guard.h

#pragma once
#include <type_traits>
#include <utility>
 
namespace asyncpp {
    template<typename TFunction>
    class scope_guard {
        TFunction m_function;
        bool m_engaged;
 
    public:
        explicit scope_guard(TFunction func,
                             bool engaged = true) noexcept(std::is_nothrow_move_constructible_v<TFunction>)
            : m_function{std::move(func)}, m_engaged{engaged} {
            static_assert(noexcept(func()), "scope_guard function must not throw exceptions");
        }
        scope_guard(const scope_guard&) = delete;
        scope_guard& operator=(const scope_guard&) = delete;
        ~scope_guard() {
            if (m_engaged) m_function();
        }
        void disengage() noexcept { m_engaged = false; }
        void engage() noexcept { m_engaged = true; }
        [[nodiscard]] bool is_engaged() const noexcept { return m_engaged; }
        TFunction& function() noexcept { return m_function; }
        const TFunction& function() const noexcept { return m_function; }
    };
} // namespace asyncpp