On Monday, January 2, 2023, Simon Scatton via Std-Proposals <
std-proposals_at_[hidden]> wrote:
>
> So that for instance if I want a thread safe Output, I use this:
> Output<std::mutex> A;
> And if I want a non-thread safe Output I use this:
> Output<NullMutex> B;
>


What if you were to pass around an 'std::optional<std::mutex>'?

Then the likes of 'lock_guard' and 'unique_lock' could be given a new
overloaded constructor:

template<class MutexType>
class lock_guard {
public:
    lock_guard(std::optional<MutexType> &arg)
    {
        if ( arg.has_value() ) p_mtx = &arg.value();
    }
};