fn require_copy(x: T) {} struct Bar { x: T } trait Foo { fn needs_copy(self) where T: Copy; fn fails_copy(self); } // Ensure constraints are only attached to methods locally impl Foo for Bar { fn needs_copy(self) where T: Copy { require_copy(self.x); } fn fails_copy(self) { require_copy(self.x); //~^ ERROR the trait bound `T: Copy` is not satisfied } } fn main() {}