remove custom post type slug in wordpress

function custom_post_type_link($permalink, $post, $leavename) {
    if (!gettype($post) == 'post') {
        return $permalink;
    }
    switch ($post->post_type) {
        case 'slug':
            $permalink = get_home_url() . '/' . $post->post_name . '/';
            break;
    }

    return $permalink;
}

add_filter(
    'post_type_link',
    'custom_post_type_link',
    10,
    3
);