Macro libuv_sys2::uv_handle

macro_rules! uv_handle {
    (&mut $a:expr) => { ... };
    (&$a:expr) => { ... };
    ($a:expr) => { ... };
}

This macro simplifies casting a reference or raw pointer to a uv_SOMETHING_t as a raw pointer to a uv_SOMETHING_ELSE_t. This is frequently necessary to cast a uv_SOMETHING_t to a uv_handle_t, but may also be used in other situations (casting a &mut uv_tty_t to a *mut uv_stream_t, for example). Really, this macro can be used to cast any reference or raw pointer to a raw pointer of a different type.

Example

let mut tty: uv_tty_t = unsafe { mem::zeroed() };

// without the macro, you'd need to cast the reference to a raw pointer of the
// same type, and then cast that as a raw pointer of the target type:
let handle: *mut uv_handle_t = &mut tty as *mut uv_tty_t as *mut uv_handle_t;

// the macro is much more wieldy:
let handle: *mut uv_handle_t = uv_handle!(&mut tty);