生成的 C++ 代码

#[cxx::bridge]
mod ffi {
    // Rust types and signatures exposed to C++.
    extern "Rust" {
        type MultiBuf;
        fn next_chunk(buf: &mut MultiBuf) -> &[u8];
    }
}

大致生成以下 C++：

struct MultiBuf final : public ::rust::Opaque {
  ~MultiBuf() = delete;
private:
  friend ::rust::layout;
  struct layout {
    static ::std::size_t size() noexcept;
    static ::std::size_t align() noexcept;
  };
};
::rust::Slice<::std::uint8_t const> next_chunk(::org::blobstore::MultiBuf &buf) noexcept;