warning: not reporting region error due to nll
  --> $DIR/issue-16683.rs:14:9
   |
LL |         self.a(); //~ ERROR cannot infer
   |         ^^^^

warning: not reporting region error due to nll
  --> $DIR/issue-16683.rs:14:14
   |
LL |         self.a(); //~ ERROR cannot infer
   |              ^

error: unsatisfied lifetime constraints
  --> $DIR/issue-16683.rs:14:9
   |
LL |     fn b(&self) {
   |          - let's call the lifetime of this reference `'1`
LL |         self.a(); //~ ERROR cannot infer
   |         ^^^^^^^^ argument requires that `'1` must outlive `'a`

error: aborting due to previous error