error[E0599]: the method `filterx` exists for struct `Map<Repeat, [closure@$DIR/issue-30786.rs:117:27: 117:34]>`, but its trait bounds were not satisfied
  --> $DIR/issue-30786.rs:118:22
   |
LL | pub struct Map<S, F> {
   | --------------------
   | |
   | method `filterx` not found for this struct
   | doesn't satisfy `_: StreamExt`
...
LL |     let filter = map.filterx(|x: &_| true);
   |                      ^^^^^^^ method cannot be called on `Map<Repeat, [closure@$DIR/issue-30786.rs:117:27: 117:34]>` due to unsatisfied trait bounds
   |
note: the following trait bounds were not satisfied:
      `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:117:27: 117:34]>: Stream`
      `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:117:27: 117:34]>: Stream`
      `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:117:27: 117:34]>: Stream`
  --> $DIR/issue-30786.rs:96:50
   |
LL | impl<T> StreamExt for T where for<'a> &'a mut T: Stream {}
   |         ---------     -                          ^^^^^^ unsatisfied trait bound introduced here

error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:129:30: 129:37]>`, but its trait bounds were not satisfied
  --> $DIR/issue-30786.rs:130:24
   |
LL | pub struct Filter<S, F> {
   | -----------------------
   | |
   | method `countx` not found for this struct
   | doesn't satisfy `_: StreamExt`
...
LL |     let count = filter.countx();
   |                        ^^^^^^ method cannot be called on `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:129:30: 129:37]>` due to unsatisfied trait bounds
   |
note: the following trait bounds were not satisfied:
      `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:129:30: 129:37]>: Stream`
      `&'a mut &mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:129:30: 129:37]>: Stream`
      `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:129:30: 129:37]>: Stream`
  --> $DIR/issue-30786.rs:96:50
   |
LL | impl<T> StreamExt for T where for<'a> &'a mut T: Stream {}
   |         ---------     -                          ^^^^^^ unsatisfied trait bound introduced here

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0599`.