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Trait1: exercises/traits/traits1.rs
题目
rust
// traits1.rs
//
// Time to implement some traits! Your task is to implement the trait
// `AppendBar` for the type `String`. The trait AppendBar has only one function,
// which appends "Bar" to any object implementing this trait.
//
// Execute `rustlings hint traits1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
trait AppendBar {
fn append_bar(self) -> Self;
}
impl AppendBar for String {
// TODO: Implement `AppendBar` for type `String`.
}
fn main() {
let s = String::from("Foo");
let s = s.append_bar();
println!("s: {}", s);
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_foo_bar() {
assert_eq!(String::from("Foo").append_bar(), String::from("FooBar"));
}
#[test]
fn is_bar_bar() {
assert_eq!(
String::from("").append_bar().append_bar(),
String::from("BarBar")
);
}
}
这次来实现一些Trait,您的任务是为String
类型实现AppendBar
Trait。这个Trait只有一个函数,它将Bar
字符串追加到实现此Trait的任何对象后面。
题目解析
rust
trait AppendBar {
fn append_bar(self) -> Self;
}
impl AppendBar for String {
// TODO: Implement `AppendBar` for type `String`.
fn append_bar(self) -> Self {
self + "Bar"
}
}