Type Alias BackCallback 

pub type BackCallback = Option<unsafe extern "C" fn(back_context: *mut c_void)>;

Back callback type

Will be called from the GUI thread

Aliased Type

pub enum BackCallback {
    None,
    Some(unsafe extern "C" fn(*mut c_void)),
}

Variants

None

No value.

Some(unsafe extern "C" fn(*mut c_void))

Some value of type T.