@dbw9580 这个该用 Unsafe 就要用 Unsafe …… Rust 设计出 Unsafe 不是拿来吓人的。C++ 实现高性能的 low-level data structure 也要用 owning raw pointer。

> This problem cannot be solved (at scale) by transforming all owning pointers to unique_ptrs and shared_ptrs, partly because we need/use owning "raw pointers" as well as simple pointers in the implementation of our fundamental resource handles. For example, common vector implementations have one owning pointer and two non-owning pointers.
-- https://github.com/isocpp/CppCoreGuidelines

libc++ 的 forward_list: https://github.com/llvm-mirror/libcxx/blob/master/include/forward_list

但是本来一般人就不应该自己实现链表这种级别的东西，除了学算法和数据结构的时候。所以也就应该用 Safe Rust 和 Smart Pointer + Non-owning raw pointer