warning: method `h` is never used
  --> $DIR/bound-subst4.rs:7:8
   |
LL | trait A<T> {
   |       - method in this trait
LL |     fn g(&self, x: usize) -> usize { x }
LL |     fn h(&self, x: T) { }
   |        ^
   |
   = note: `#[warn(dead_code)]` on by default

warning: 1 warning emitted