concept indirectly_copyable_storable =
    std::indirectly_copyable<In, Out> &&
    std::indirectly_writable<Out, std::iter_value_t<In>&> &&
    std::indirectly_writable<Out, const std::iter_value_t<In>&> &&
    std::indirectly_writable<Out, std::iter_value_t<In>&&> &&
    std::indirectly_writable<Out, const std::iter_value_t<In>&&> &&
    std::copyable<std::iter_value_t<In>> &&
    std::constructible_from<std::iter_value_t<In>, std::iter_reference_t<In>> &&

std::assignable_from<std::iter_value_t<In>&, std::iter_reference_t<In>>;