error[E0401]: can't use generic parameters from outer item
  --> $DIR/issue-3021-c.rs:4:24
   |
LL | fn siphash<T>() {
   |            - type parameter from outer item
LL |
LL |     trait U {
   |            - help: try introducing a local generic parameter here: `<T>`
LL |         fn g(&self, x: T) -> T;
   |                        ^ use of generic parameter from outer item

error[E0401]: can't use generic parameters from outer item
  --> $DIR/issue-3021-c.rs:4:30
   |
LL | fn siphash<T>() {
   |            - type parameter from outer item
LL |
LL |     trait U {
   |            - help: try introducing a local generic parameter here: `<T>`
LL |         fn g(&self, x: T) -> T;
   |                              ^ use of generic parameter from outer item

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0401`.