fter Rust 1.30.0, it was re-exported by
this definition. For more information, please read [RFC 2521].

[Nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs
[RFC 2521]: https://github.com/rust-lang/rfcs/blob/master/text/2521-c_void-reunification.md