Rust实现构建器模式和如何使用Bon库中的构建器

#[derive(Debug)]
struct Person {
    name: String,
    age: u32,
    address: Option<String>,
    sex: Option<String>,
}
struct PersonBuilder {
    name: String,
    age: u32,
    address: Option<String>,
    sex: Option<String>,
}
impl PersonBuilder {
    fn new(name: String, age: u32) -> Self {
        Self {
            name,
            age,
            address: None,
            sex: None,
        }
    }
    fn with_address(mut self, address: String) -> Self {
        self.address = Some(address);
        self
    }
    fn with_sex(mut self, sex: String) -> Self {
        self.sex = Some(sex);
        self
    }
    fn build(self) -> Person {
        Person {
            name: self.name,
            age: self.age,
            address: self.address,
            sex: self.sex,
        }
    }
}
fn main() {
    let person = PersonBuilder::new("Alice".to_string(), 30)
        .with_address("Wonderland".to_string())
        .with_sex("Female".to_string())
        .build();
    println!("{:?}", person);
    // Access the fields to demonstrate usage
    println!("Name: {}", person.name);
    println!("Age: {}", person.age);
    if let Some(address) = &person.address {
        println!("Address: {}", address);
    } else {
        println!("Address: None");
    }
    if let Some(sex) = &person.sex {
        println!("Sex: {}", sex);
    } else {
        println!("Sex: None");
    }
}

Person { name: "Alice", age: 30, address: Some("Wonderland"), sex: Some("Female") }
Name: Alice
Age: 30
Address: Wonderland
Sex: Female

[dependencies]
bon = "1.1.0"

use bon::bon;
#[derive(Debug)]
struct Person {
    name: String,
    age: u32,
    address: Option<String>,
    sex: Option<String>,
}
#[bon] // 使用 Bon 库的宏
impl Person {
    #[builder]
    fn new(name: String, age: u32) -> Self {
        Self {
            name,
            age,
            address: None,
            sex: None,
        }
    }
    #[builder]
    fn with_address(&mut self, address: String) {
        self.address = Some(address);    
    }
    #[builder]
    fn with_sex(&mut self, sex: String) {
        self.sex = Some(sex);
    }
}
fn main() {
    let mut person = Person::builder()
        .name("Alice".to_string())
        .age(30)    
        .build();
    person.with_address().address("Wonderland").call();
    person.with_sex().sex("Female").call();
    println!("{:?}", person);
    println!("Name: {}", person.name);
    println!("Age: {}", person.age);
    if let Some(address) = &person.address {
        println!("Address: {}", address);
    } else {
        println!("Address: None");
    }
    if let Some(sex) = &person.sex {
        println!("Sex: {}", sex);
    } else {
        println!("Sex: None");
    }
}

Person { name: "Alice", age: 30, address: Some("Wonderland"), sex: Some("Female") }
Name: Alice
Age: 30
Address: Wonderland
Sex: Female

fn main() {
    #[bon::builder] 
    fn greet(name: &str, age: u32) -> String {
        format!("Hello {name} with age {age}!")
    }
    let greeting = greet()
        .name("Bon") 
        .age(24)   
        .call();
    if greeting == "Hello Bon with age 24!" {
        println!("Assertion passed: {}", greeting);
    } else {
        println!("Assertion failed");
    }
}

Assertion passed: Hello Bon with age 24!