error: `#[unstable_feature_bound]` attribute cannot be used on required trait methods
  --> $DIR/unstable_inherent_method.rs:11:5
   |
LL |     #[unstable_feature_bound(foo)]
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: `#[unstable_feature_bound]` can be applied to functions, trait impl blocks, and traits

error: `#[unstable_feature_bound]` attribute cannot be used on trait methods in impl blocks
  --> $DIR/unstable_inherent_method.rs:18:5
   |
LL |     #[unstable_feature_bound(foo)]
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: `#[unstable_feature_bound]` can be applied to functions, trait impl blocks, and traits

error: aborting due to 2 previous errors