Memory Traits

Traits สำหรับ memory management

Drop Trait

struct Resource {
    name: String,
}

impl Drop for Resource {
    fn drop(&mut self) {
        println!("Dropping: {}", self.name);
    }
}

fn main() {
    println!("=== Drop Order ===");
    {
        let a = Resource { name: "A".to_string() };
        let b = Resource { name: "B".to_string() };
        println!("Created A and B");
    }  // B drops first, then A (LIFO)

    println!("\n=== Manual Drop ===");
    let c = Resource { name: "C".to_string() };
    println!("Before drop");
    drop(c);  // Explicit drop
    println!("After drop\n");

    // Tuple/struct field order
    println!("=== Field Order ===");
    struct Container {
        first: Resource,
        second: Resource,
    }

    let _container = Container {
        first: Resource { name: "First".to_string() },
        second: Resource { name: "Second".to_string() },
    };
    // Fields drop in declaration order

    println!("End of main");
}