Function errors

include/fplus/filter.hpp:291–302

        typename internal::same_cont_new_t<ContainerIn,
            typename ContainerIn::value_type::error_t>::type>
ContainerOut errors(const ContainerIn& xs)
{
    typedef typename ContainerIn::value_type::ok_t Ok;
    typedef typename ContainerIn::value_type::error_t Error;
    auto errorsInResults = keep_if(is_error<Ok, Error>, xs);
    ContainerOut ys;
    internal::prepare_container(ys, fplus::size_of_cont(errorsInResults));
    auto itOut = internal::get_back_inserter(ys);
    std::transform(std::begin(errorsInResults), std::end(errorsInResults),
        itOut, unsafe_get_error<Ok, Error>);
    return ys;
}

// API search type: trim_left : (a, [a]) -> [a]
// fwd bind count: 1