Type Alias LPWAVECALLBACK
pub type LPWAVECALLBACK = Option<unsafe extern "system" fn(hdrvr: HDRVR, umsg: u32, dwuser: usize, dw1: usize, dw2: usize)>;Aliased Type§
pub enum LPWAVECALLBACK {
None,
Some(unsafe extern "system" fn(HDRVR, u32, usize, usize, usize)),
}