fn main() {
    #macro([#zip_or_unzip[[x, ...], [y, ...]], [[x, y], ...]],
           [#zip_or_unzip[[xx, yy], ...], [[xx, ...], [yy, ...]]]);


    assert (#zip_or_unzip[[1, 2, 3, 4], [5, 6, 7, 8]] ==
                [[1, 5], [2, 6], [3, 7], [4, 8]]);
    assert (#zip_or_unzip[[1, 5], [2, 6], [3, 7], [4, 8]] ==
                [[1, 2, 3, 4], [5, 6, 7, 8]]);


    #macro([#nested[[[x, ...], ...], [[y, ...], ...]],
            [[[x, y], ...], ...]]);
    assert (#nested[[[1, 2, 3, 4, 5], [7, 8, 9, 10, 11, 12]],
                    [[-1, -2, -3, -4, -5], [-7, -8, -9, -10, -11, -12]]] ==
                [[[1, -1], [2, -2], [3, -3], [4, -4], [5, -5]],
                 [[7, -7], [8, -8], [9, -9], [10, -10], [11, -11],
                  [12, -12]]]);

    #macro([#dup[y, [x, ...]], [[y, x], ...]]);

    assert (#dup[1, [1, 2, 3, 4]] == [[1, 1], [1, 2], [1, 3], [1, 4]]);


    #macro([#lambda[x, #<t>, body, #<s>],
            {
                fn result(x: t) -> s { ret body }
                result
            }]);


    assert ((#lambda[i, #<uint>, i + 4u, #<uint>])(12u) == 16u)

}