트레잇(Trait)
A trait can require that types implementing it also implement other traits, called supertraits. Here, any type implementing Pet
must implement Animal
.
trait Animal { fn leg_count(&self) -> u32; } trait Pet: Animal { fn name(&self) -> String; } struct Dog(String); impl Animal for Dog { fn leg_count(&self) -> u32 { 4 } } impl Pet for Dog { fn name(&self) -> String { self.0.clone() } } fn main() { let puppy = Dog(String::from("렉스")); println!("{} has {} legs", puppy.name(), puppy.leg_count()); }
This is sometimes called "trait inheritance" but students should not expect this to behave like OO inheritance. It just specifies an additional requirement on implementations of a trait.