warning: lifetime flowing from input to output with different syntax can be confusing
  --> $DIR/self_lifetime.rs:7:23
   |
LL |     fn foo<'b>(self: &'b Foo<'a>) -> &() { self.0 }
   |                       ^^             --- the lifetime gets resolved as `'b`
   |                       |
   |                       this lifetime flows to the output
   |
   = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
help: one option is to consistently use `'b`
   |
LL |     fn foo<'b>(self: &'b Foo<'a>) -> &'b () { self.0 }
   |                                       ++

warning: lifetime flowing from input to output with different syntax can be confusing
  --> $DIR/self_lifetime.rs:13:36
   |
LL |     fn bar<'a>(self: &Alias, arg: &'a ()) -> &() { arg }
   |                                    ^^        --- the lifetime gets resolved as `'a`
   |                                    |
   |                                    this lifetime flows to the output
   |
help: one option is to consistently use `'a`
   |
LL |     fn bar<'a>(self: &Alias, arg: &'a ()) -> &'a () { arg }
   |                                               ++

warning: 2 warnings emitted