pub type PFNGLGETUNIFORMIVARBPROC = Option<unsafe extern "C" fn(programObj: GLhandleARB, location: GLint, params: *mut GLint)>;
enum PFNGLGETUNIFORMIVARBPROC { None, Some(unsafe extern "C" fn(_: u32, _: i32, _: *mut i32)), }
No value.
Some value of type T.
T