pub type PFNGLSECONDARYCOLOR3SPROC = Option<unsafe extern "C" fn(red: GLshort, green: GLshort, blue: GLshort)>;
enum PFNGLSECONDARYCOLOR3SPROC { None, Some(unsafe extern "C" fn(_: i16, _: i16, _: i16)), }
No value.
Some value of type T.
T