a := New(WithShape(4, 2), WithBacking([]float64{1, 1, 1, 1, 1, 1, 1, 1}))
b := New(WithShape(2, 4), WithBacking([]float64{0, 1, 0, 1, 0, 1, 0, 1}))
c, _ := a.MatMul(b)
d, err := Div(c, 2) // 2 is an untyped constant that will be used as an int.
if err == nil {
log.Fatal("expected an error")
}