pub type LPALCISEXTENSIONPRESENT = Option<unsafe extern "C" fn(_: *mut ALCdevice, _: *const i8) -> i8>;
enum LPALCISEXTENSIONPRESENT { None, Some(unsafe extern "C" fn(_: *mut ALCdevice, _: *const i8) -> i8), }
No value.
Some value of type T.
T