pub enum Rect<'a> { None(*const AVSubtitleRect), Bitmap(Bitmap<'a>), Text(Text<'a>), Ass(Ass<'a>), }
self
TypeId
原样返回参数。
Calls U::from(self).
U::from(self)
That is, this conversion is whatever the implementation of From<T> for U 实现选择执行的操作。
From<T> for U