allZero

ubyte[20] d;
assert(d.allZero);	 // note that [] is needed here

ubyte[2][2] zeros = [ [0, 0],
					  [0, 0] ];
assert(zeros.allZero);

ubyte[2][2] one = [ [0, 1],
					[0, 0] ];
assert(!one.allZero);

ubyte[2][2] ones = [ [1, 1],
					 [1, 1] ];
assert(!ones.allZero);

ubyte[2][2][2] zeros3d = [ [ [0, 0],
							 [0, 0] ],
						   [ [0, 0],
							 [0, 0] ] ];
assert(zeros3d.allZero);

ubyte[2][2][2] ones3d = [ [ [1, 1],
							[1, 1] ],
						  [ [1, 1],
							[1, 1] ] ];
assert(!ones3d.allZero);

struct Vec { real x, y; }
const v0 = Vec(0, 0);
assert(v0.zeroed);
const v1 = Vec(1, 1);
assert(!v1.zeroed);

class Vec
{
	this(real x, real y) { this.x = x; this.y = y; }
	real x, y;
}
const v0 = new Vec(0, 0);
assert(v0.zeroed);
const v1 = new Vec(1, 1);
assert(!v1.zeroed);