不安全 Rust

This segment should take about 1 hour and 5 minutes. It contains:

Slide Duration
Unsafe 5 minutes
解引用裸指针 10 minutes
可变的静态变量 5 minutes
联合体 5 minutes
Unsafe 函数 5 minutes
Unsafe 特征 5 minutes
练习：FFI 封装容器 30 minutes