我需要帮助了解终身说明符。我想我得到了生命的概念。我看了Memory, Ownership and Lifetimes。我只是想如果我可以通过这个小example来解决它,它可能会帮助我解决生命周期的语法问题。到目前为止,我发现一个令人困惑的话题。
use std::collections::HashMap;
fn main() {
pub struct User<'a> {
pub name: & 'a str
}
impl <'a>User<'a> {
pub fn new(uname: & 'a str, pwd: & 'a str) -> User {
User{name: uname}
}
}
pub struct ChatRoom<'a> {
pub name: & 'a str,
pub users: HashMap<& 'a str, User>
}
impl <'a>ChatRoom<'a> {
pub fn new(name: &str) -> ChatRoom {
let users = HashMap::new();
ChatRoom {name: name, users: users}
}
pub fn join(&mut self, user: User) {
self.users.insert(user.name, user);
}
}
let mut room = ChatRoom::new("Test");
let user = User::new("bender","123");
room.join(user);
}
答案 0 :(得分:3)
我不确定你的确切问题是什么,所以我想你想要编译代码。请检查此playground。
请注意,生命周期参数是该类型的一部分,因此您希望User<'a>
不仅仅是User
。
use std::collections::HashMap;
fn main() {
struct User<'a> {
name: &'a str,
}
impl<'a> User<'a> {
fn new(uname: &'a str, pwd: &'a str) -> User<'a> {
User { name: uname }
}
}
struct ChatRoom<'a> {
name: &'a str,
users: HashMap<&'a str, User<'a>>,
}
impl<'a> ChatRoom<'a> {
fn new(name: &str) -> ChatRoom {
let users = HashMap::new();
ChatRoom {
name: name,
users: users,
}
}
fn join(&mut self, user: User<'a>) {
self.users.insert(user.name, user);
}
}
let mut room = ChatRoom::new("Test");
let user = User::new("bender", "123");
room.join(user);
}