import mir.ndslice.allocation : slice;
auto a = slice!int(2, 3);

a[0..$, 0..$-1] += [[1, 2], [3, 4]];
assert(a == [[1, 2, 0], [3, 4, 0]]);

a[0..$, 0..$-1] += [1, 2];
assert(a == [[2, 4, 0], [4, 6, 0]]);

a[1, 0..$-1] += [3, 4];
assert(a[1] == [7, 10, 0]);

a[1, 0..$-1][] += [1, 2];
assert(a[1] == [8, 12, 0]);

import mir.ndslice.allocation : slice;
import mir.ndslice.topology : blocks;
auto a = slice!int(4, 4);
a.blocks(2, 2)[] += [[0, 1], [2, 3]];

assert(a ==
        [[0, 0, 1, 1],
         [0, 0, 1, 1],
         [2, 2, 3, 3],
         [2, 2, 3, 3]]);