Enumerator::Lazy#uniq

static VALUE
lazy_uniq(VALUE obj)
{
    const lazyenum_funcs *const funcs =
        rb_block_given_p() ? &lazy_uniq_iter_funcs : &lazy_uniq_funcs;
    return lazy_add_method(obj, 0, 0, Qnil, Qnil, funcs);
}