pub type PFNGLBINDATTRIBLOCATIONPROC = Option<unsafe extern "C" fn(program: GLuint, index: GLuint, name: *const GLchar)>;
enum PFNGLBINDATTRIBLOCATIONPROC { None, Some(unsafe extern "C" fn(_: u32, _: u32, _: *const i8)), }
No value.
Some value of type T.
T