Merkmale
Rust lets you abstract over types with traits. They're similar to interfaces:
struct Dog { name: String, age: i8, } struct Cat { lives: i8, } trait Pet { fn talk(&self) -> String; fn greet(&self) { println!("Oh you're a cutie! What's your name? {}", self.talk()); } } impl Pet for Dog { fn talk(&self) -> String { format!("Woof, my name is {}!", self.name) } } impl Pet for Cat { fn talk(&self) -> String { String::from("Miau!") } } fn main() { let captain_floof = Cat { lives: 9 }; let fido = Dog { name: String::from("Fido"), age: 5 }; captain_floof.greet(); fido.greet(); }
This slide should take about 10 minutes.
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A trait defines a number of methods that types must have in order to implement the trait.
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Traits are implemented in an
impl <trait> for <type> { .. }
block. -
Traits may specify pre-implemented (provided) methods and methods that users are required to implement themselves. Provided methods can rely on required methods. In this case,
greet
is provided, and relies ontalk
.