error[E0284]: type annotations needed
  --> $DIR/issue-12028.rs:27:14
   |
LL |         self.input_stream(&mut stream);
   |              ^^^^^^^^^^^^
   |
   = note: cannot satisfy `<_ as StreamHasher>::S == <H as StreamHasher>::S`
help: try using a fully qualified path to specify the expected types
   |
LL |         <u8 as StreamHash<H>>::input_stream(self, &mut stream);
   |         ++++++++++++++++++++++++++++++++++++    ~

error: aborting due to previous error

For more information about this error, try `rustc --explain E0284`.