fn main()
{
	//--
	let mut a = 40;
	let b = &mut a;
	*b+= 2;
	println!("a = {}", a);

	//--
	//let mut a2 = 40;
	//{
	//	let b2 = &mut a2;
	//	*b2+= 2;
	//}
	//println!("a = {}", a2);

    //--
	//let mut z = vec![3,2,1];
	//for i in &z
	//{
		//println!("i = {}", i);
		////z.push(5)
	//}
}