pub type PFNGLVERTEXSTREAM3IATIPROC = Option<unsafe extern "C" fn(stream: GLenum, x: GLint, y: GLint, z: GLint)>;
enum PFNGLVERTEXSTREAM3IATIPROC { None, Some(unsafe extern "C" fn(_: u32, _: i32, _: i32, _: i32)), }
No value.
Some value of type T.
T