error[E0308]: mismatched types
  --> $DIR/issue-13853.rs:14:9
   |
LL |     fn nodes<'a, I: Iterator<Item=&'a N>>(&self) -> I
   |                  - this type parameter              - expected `I` because of return type
...
LL |         self.iter()
   |         ^^^^^^^^^^^ expected type parameter `I`, found `Iter<'_, N>`
   |
   = note: expected type parameter `I`
                      found struct `std::slice::Iter<'_, N>`

error[E0599]: no method named `iter` found for reference `&G` in the current scope
  --> $DIR/issue-13853.rs:27:23
   |
LL |     for node in graph.iter() {
   |                       ^^^^ method not found in `&G`

error[E0308]: mismatched types
  --> $DIR/issue-13853.rs:37:13
   |
LL |     iterate(graph);
   |     ------- ^^^^^
   |     |       |
   |     |       expected `&_`, found `Vec<Stuff>`
   |     |       help: consider borrowing here: `&graph`
   |     arguments to this function are incorrect
   |
   = note: expected reference `&_`
                 found struct `Vec<Stuff>`
note: function defined here
  --> $DIR/issue-13853.rs:26:4
   |
LL | fn iterate<N: Node, G: Graph<N>>(graph: &G) {
   |    ^^^^^^^                       ---------

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0308, E0599.
For more information about an error, try `rustc --explain E0308`.