fn require_copy<T: Copy>(x: T) {} struct Bar<T> { x: T } trait Foo<T> { fn needs_copy(self) where T: Copy; fn fails_copy(self); } // Ensure constraints are only attached to methods locally impl<T> Foo<T> for Bar<T> { 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() {}