Revert "认领“类和结构体”"

This reverts commit 69e8107d5dd8c28d5eaa02f63c43aea0fc686a36.
Revert "Revert "认领“类和结构体”""

This reverts commit c41cacc6f3bb7d2d31908a6e2219200f720ec507.
Revert "帮胡衍明认领可选链"

This reverts commit 2100ba9be37d5051a3636edfb96aa0a82450ac53.
帮胡衍明认领泛型