Type Alias MSGBOXCALLBACK 

pub type MSGBOXCALLBACK = Option<unsafe extern "system" fn(lphelpinfo: *mut HELPINFO)>;

Aliased Type

pub enum MSGBOXCALLBACK {
    None,
    Some(unsafe extern "system" fn(*mut HELPINFO)),
}

Variants

None

No value.

Some(unsafe extern "system" fn(*mut HELPINFO))

Some value of type T.