pub type PFNGLPROGRAMUNIFORM1FEXTPROC = Option<unsafe extern "C" fn(program: GLuint, location: GLint, v0: GLfloat)>;
enum PFNGLPROGRAMUNIFORM1FEXTPROC { None, Some(unsafe extern "C" fn(_: u32, _: i32, _: f32)), }
No value.
Some value of type T.
T