健康统计

你正在实现一个健康监控系统。作为其中的一部分，你需要对用户的健康统计数据进行追踪。

User 结构体的定义和 impl 块中一些函数的框架已经给出。你的目标是实现在 impl 块中定义的 User struct 的方法。

将以下代码复制到 https://play.rust-lang.org/，并填充缺失的方法：

// TODO: remove this when you're done with your implementation.
#![allow(unused_variables, dead_code)]

pub struct User {
    name: String,
    age: u32,
    height: f32,
    visit_count: usize,
    last_blood_pressure: Option<(u32, u32)>,
}

pub struct Measurements {
    height: f32,
    blood_pressure: (u32, u32),
}

pub struct HealthReport<'a> {
    patient_name: &'a str,
    visit_count: u32,
    height_change: f32,
    blood_pressure_change: Option<(i32, i32)>,
}

impl User {
    pub fn new(name: String, age: u32, height: f32) -> Self {
        todo!("Create a new User instance")
    }

    pub fn name(&self) -> &str {
        todo!("Return the user's name")
    }

    pub fn age(&self) -> u32 {
        todo!("Return the user's age")
    }

    pub fn height(&self) -> f32 {
        todo!("Return the user's height")
    }

    pub fn doctor_visits(&self) -> u32 {
        todo!("Return the number of time the user has visited the doctor")
    }

    pub fn set_age(&mut self, new_age: u32) {
        todo!("Set the user's age")
    }

    pub fn set_height(&mut self, new_height: f32) {
        todo!("Set the user's height")
    }

    pub fn visit_doctor(&mut self, measurements: Measurements) -> HealthReport {
        todo!("Update a user's statistics based on measurements from a visit to the doctor")
    }
}

fn main() {
    let bob = User::new(String::from("Bob"), 32, 155.2);
    println!("I'm {} and my age is {}", bob.name(), bob.age());
}

#[test]
fn test_height() {
    let bob = User::new(String::from("Bob"), 32, 155.2);
    assert_eq!(bob.height(), 155.2);
}

#[test]
fn test_set_age() {
    let mut bob = User::new(String::from("Bob"), 32, 155.2);
    assert_eq!(bob.age(), 32);
    bob.set_age(33);
    assert_eq!(bob.age(), 33);
}

#[test]
fn test_visit() {
    let mut bob = User::new(String::from("Bob"), 32, 155.2);
    assert_eq!(bob.doctor_visits(), 0);
    let report = bob.visit_doctor(Measurements {
        height: 156.1,
        blood_pressure: (120, 80),
    });
    assert_eq!(report.patient_name, "Bob");
    assert_eq!(report.visit_count, 1);
    assert_eq!(report.blood_pressure_change, None);

    let report = bob.visit_doctor(Measurements {
        height: 156.1,
        blood_pressure: (115, 76),
    });

    assert_eq!(report.visit_count, 2);
    assert_eq!(report.blood_pressure_change, Some((-5, -4)));
}