error[E0034]: multiple applicable items in scope
  --> $DIR/inference_unstable_featured.rs:16:20
   |
LL |     assert_eq!('x'.ipu_flatten(), 0);
   |                    ^^^^^^^^^^^ multiple `ipu_flatten` found
   |
   = note: candidate #1 is defined in an impl of the trait `IpuIterator` for the type `char`
   = note: candidate #2 is defined in an impl of the trait `IpuItertools` for the type `char`
help: disambiguate the method for candidate #1
   |
LL |     assert_eq!(IpuIterator::ipu_flatten(&'x'), 0);
   |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
help: disambiguate the method for candidate #2
   |
LL |     assert_eq!(IpuItertools::ipu_flatten(&'x'), 0);
   |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0034`.