Macro nix::request_code_readwrite

macro_rules! request_code_readwrite {
    ($g:expr, $n:expr, $len:expr) => { ... };
}

Generate an ioctl request code for a command that reads and writes.

This is equivalent to the _IOWR() macro exposed by the C ioctl API.

You should only use this macro directly if the ioctl you're working with is "bad" and you cannot use ioctl_readwrite!() directly.