6.1 Trait && generics
Traits
- Similar to interfaces and abstract classes
- Add defined behavior to the structure
impl trait_demo for struct_demo
struct Steve {
name: String,
}
impl Person for Steve {
fn new(name_str: String) -> Self {
Steve {
name: name_str }
}
fn language(&self) -> &str {
"Steve"
}
}
struct Alex {
name: String,
}
impl Person for Alex {
fn new(name_str: String) -> Self {
Alex {
name: name_str }
}
fn language(&self) -> &str {
"Alex"
}
fn eat_food(&self) {
println!("Eat fish!");
}
}
trait Person {
fn new(name_str: String) -> Self;
fn language(&self) -> &str;
fn eat_food(&self) {
println!("Eat food");
}
}
fn main() {
let a = Steve::new("Star_tears".to_string());
let b = Alex::new("T_dream".to_string());
a.eat_food();
b.eat_food();
}
-
return enumeration
-
fn get_trait -> Box<dyn trait_name>
-
generic
- Generic programming (
generic programming) is a style or paradigm of a programming language - Generics allow programmers to use some later-specified types when writing code in a strongly typed programming language, and specify these types as parameters when instantiating
trait Bark {
fn bark(&self) -> String;
}
struct Dog {
species: String,
}
struct Cat {
color: String,
}
impl Bark for Dog {
fn bark(&self) -> String {
format!("{} barking", self.species)
}
}
fn bark<T: Bark>(b: T) {
println!("{}", b.bark());
}
fn main() {
let dog = Dog {
species: "white dog".to_string(),
};
bark(dog);
}