import mir.ndslice.slice: sliced, Slice;

auto a = iota(3, 4, 5, 6);
auto b = a.pack!2;

static immutable res1 = [3, 4];
static immutable res2 = [5, 6];
assert(b.shape == res1);
assert(b[0, 0].shape == res2);
assert(a == b.unpack);
assert(a.pack!2 == b);
static assert(is(typeof(b) == typeof(a.pack!2)));