Rust swap

    /*fn swap<'a>(a: &'a mut String, b:&'a mut String){
        let tmp = *a;
        *a = *b;
        *b = tmp;
    }
    
    let mut a = "aaa".to_string();
    let mut b = "bbb".to_string();
    
    swap(&mut a, &mut b);*/


    let mut a = 111;
    let mut b = 222;
    
    fn swap<'a>(a: &'a mut i32, b:&'a mut i32){
        let tmp = *a;
        *a = *b;
        *b = tmp;
    }


    /*
    fn swap(mut a:  i32, mut b:  i32){
        let tmp = a;
        a = b;
        b = tmp;
    }
    swap( a,  b);
    */
    
    swap(&mut a, &mut b);

最高效方式

    let mut a = "aaa".to_string();
    let mut b = "bbb".to_string();
    
    std::mem::swap(&mut a, &mut b);