gluon_base::types
pub trait Walker<T> { fn walk(&mut self, typ: &T); }
fn walk(&mut self, typ: &T)
impl<F: ?Sized> Walker<ArcKind> for F where F: FnMut(&ArcKind)
impl<I, T, F: ?Sized> Walker<T> for F where F: FnMut(&T), T: Deref<Target=Type<I, T>>