pub type PFNGLMULTITEXCOORD3SPROC = Option<unsafe extern "C" fn(target: GLenum, s: GLshort, t: GLshort, r: GLshort)>;
enum PFNGLMULTITEXCOORD3SPROC { None, Some(unsafe extern "C" fn(_: u32, _: i16, _: i16, _: i16)), }
No value.
Some value of type T.
T