type a
type a = _
type a = !
type a = bool
type a = result::Result
type a = <::i32 as Vec<bool>>::MAX
type a = [bool]
type a = [[bool]]
type a = [bool; 8]
type a = *const bool
type a = *mut bool
type a = &bool
type a = &'a mut bool
type a = &[bool]
type a = &'a bool
type a = ()
type a = (bool)
type a = (bool, usize)
type a = _
type a = unsafe extern "C" fn(bool) -> usize
type a = dyn Result + Iterator<T> + 'static + Sized
type a = impl Result + Iterator<T> + 'static + Sized
type a = for<'a, 'b: 'a> Foo<&'a Bar>
type a = a!("a")
type a<T> where T: Iterator = Option<T>