struct WindowTimerImpl : public WindowTimerBase
{
//...

    WindowTimerImpl(HWND h, UINT_PTR id, timeout_t timeoutMs) {}

    static
    WindowTimerImpl create(HWND h, UINT_PTR requestedId, timeout_t timeoutMs)
    {
        auto id = ::SetTimer(h, requestedId, timeoutMs, 0);

        if (id==0)
        {
            throw std::runtime_error("Failed to create WindowTimer");
        }

        return WindowTimerImpl(h, id, timeoutMs, true);
        // return std::move(WindowTimerImpl(h, id, timeoutMs, true)); // !!! move version
    }

//...
};

    virtual WindowTimer createTimer(timeout_t timeoutMs) const override
    {
        auto pSharedImpl = std::make_shared<WindowTimerImpl>(WindowTimerImpl::create(getHwnd(), curTimerId++, timeoutMs));

//...

template <class _Ty, class... _Types>
_CONSTEXPR20_DYNALLOC void _Construct_in_place(_Ty& _Obj, _Types&&... _Args) noexcept(
    is_nothrow_constructible_v<_Ty, _Types...>) {
#ifdef __cpp_lib_constexpr_dynamic_alloc
    if (_STD is_constant_evaluated()) {
        _STD construct_at(_STD addressof(_Obj), _STD forward<_Types>(_Args)...);
    } else
#endif // __cpp_lib_constexpr_dynamic_alloc
    {
        ::new (_Voidify_iter(_STD addressof(_Obj))) _Ty(_STD forward<_Types>(_Args)...); // !!!
    }
}