如何在 C 语言里使用 INF 和 NAN？¶
Many settings backends (including dconf) have lazy initialisation which means in the common case of the user using their computer without modifying any settings a lot of work can be avoided. For dconf, the D-Bus service doesn’t even need to be started in this case. For this reason, you should only ever modify GSettings keys in response to explicit user action.
大部分的 settings backend 都是惰性初始化的，因此若 application 只在用户显式地修改配置时修改 settings 中的 key，可以避免很多开销。(?)
The built-in g_settings_bind() functionality is careful not to write settings in response to notify signals as a result of modifications that it makes to widgets.
小心因为 widget 和 setting 绑定导致的死循环。
Normally, a schema has a fixed path that determines where the settings are stored in the conceptual global tree of settings. However, schemas can also be ‘relocatable’,
提供了一个 relocatable 的机制允许为变化的路径指定 schema。
Document Type Definition： https://gitlab.gnome.org/GNOME/glib/-/blob/master/gio/gschema.dtd