相关疑难解决方法(0)

我正在尝试使用创建内存数据库HashMap.我有一个结构Person:

struct Person {
    id: i64,
    name: String,
}

impl Person {
    pub fn new(id: i64, name: &str) -> Person {
        Person {
            id: id,
            name: name.to_string(),
        }
    }

    pub fn set_name(&mut self, name: &str) {
        self.name = name.to_string();
    }
}

我有结构Database:

use std::collections::HashMap;
use std::sync::Arc;
use std::sync::Mutex;

struct Database {
    db: Arc<Mutex<HashMap<i64, Person>>>,
}

impl Database {
    pub fn new() -> Database {
        Database {
            db: Arc::new(Mutex::new(HashMap::new())),
        }
    }

    pub fn add_person(&mut self, …