IndexAssign

test.rs

use std::cell::Cell;

trait IndexAssign<IDX, RHS>
{
	fn index_assign(self, idx: IDX, rhs: RHS);
}

struct ArrayLike
{
	arr: Vec<Cell<u32>>
}

impl ArrayLike
{
	fn assign_mul(&self, mul: u32, rhs: &ArrayLike)
	{
		for i in range(0, self.arr.len())
		{
			self.index_assign(i, rhs.arr.get(i).get() * mul);
		}
	}
}

impl<'l> IndexAssign<uint, u32> for &'l ArrayLike
{
	fn index_assign(self, idx: uint, rhs: u32)
	{
		self.arr.get(idx).set(rhs)
	}
}

impl<'l> IndexAssign<uint, bool> for &'l mut i32
{
	fn index_assign(self, idx: uint, rhs: bool)
	{
		let m = 1 << idx;
		if rhs
		{
			(*self) |= m;
		}
		else
		{
			(*self) &= !m;
		}
	}
}

fn main()
{
	let arr = ArrayLike{ arr: vec![Cell::new(1)] };
	arr.index_assign(0, 2);
	arr.assign_mul(2, &arr);
	
	let mut i = 0i32;
	i.index_assign(3, true);
	println!("{}", i);
	
}