pub type PFNGLUNIFORM3UIPROC = Option<unsafe extern "C" fn(_: i32, _: u32, _: u32, _: u32)>;
enum PFNGLUNIFORM3UIPROC { None, Some(unsafe extern "C" fn(_: i32, _: u32, _: u32, _: u32)), }
No value.
Some value of type T.
T