Vector.this

auto v1 = Vector2I(4, 2);
assert (v1.v == [4, 2]);
auto v2 = Vector2I(5);
assert (v2.v == [5, 5]);
auto v3 = Vector3I([1, 2, 3]);
assert (v3.v == [1, 2, 3]);
auto v4 = Vector4I();
assert (v4.v == [0, 0, 0, 0]);
auto v5 = Vector3I(Vector2I(1, 3), 5);
assert (v5.v == [1, 3, 5]);
auto v6 = Vector4I(Vector3I(-2, 1, 3), 5);
assert (v6.v == [-2, 1, 3, 5]);
auto v7 = Vector4I(Vector2I(1, 3), Vector2I(5, 4));
assert (v7.v == [1, 3, 5, 4]);