pub type PFNGLNORMALSTREAM3SATIPROC = Option<unsafe extern "C" fn(stream: GLenum, x: GLshort, y: GLshort, z: GLshort)>;
enum PFNGLNORMALSTREAM3SATIPROC { None, Some(unsafe extern "C" fn(_: u32, _: i16, _: i16, _: i16)), }
No value.
Some value of type T.
T