Persistent variable

We override operator= in a wrapper to create variables with custom storage

struct nxi : ndb::persistent_group
{
    using persistent_group::persistent_group;

    struct : ndb::persistent_group
    {
        using persistent_group::persistent_group;

        ndb::persistent<std::string> home{ this, "home", "test" };
        ndb::persistent<bool> zeta{ this, "zeta" };

        struct : ndb::persistent_group
        {
            using persistent_group::persistent_group;

            ndb::persistent<int> min_width{ this, "min_width" };
            ndb::persistent<std::string> max_width{ this, "max_width" };
        } tabs{ this, "tabs" };
    } browser{ this, "browser" };
};

Usage

::nxi nxi{ "nxi" };
nxi.browser.home = std::string("dev.neuroshok.com");
nxi.browser.tabs.max_width = "10";
nxi.browser.tabs.min_width = 20;
nxi.browser.zeta = true;