A good reminder. It is surprising first time you encounter it. Same for Rust. As https://doc.rust-lang.org/stable/std/io/fn.copy.html https://doc.rust-lang.org

A good reminder. It is surprising first time you encounter it. Same for Rust. As https://doc.rust-lang.org/stable/std/io/fn.copy.html https://doc.rust-lang.org/stable/std/io/fn.copy.html says, std::io::copy can use copy_file_range(2), sendfile(2), or splice(2).