Function instead_of_if_empty

include/fplus/container_common.hpp:2229–2234

template <typename Container, typename ContainerAlt,
    typename ContainerOut = internal::remove_const_and_ref_t<Container>>
ContainerOut instead_of_if_empty(const ContainerAlt& alt, Container&& xs)
{
    return instead_of_if(
        is_empty<internal::remove_const_and_ref_t<Container>>,
        alt, std::forward<Container>(xs));
}

} // namespace fplus