# operator - method

- OffsetBase other

Binary subtraction operator for Size.

Subtracting a Size from a Size returns the Offset that describes how
much bigger the left-hand-side operand is than the right-hand-side
operand. Adding that resulting Offset to the Size that was the
right-hand-side operand would return a Size equal to the Size that was
the left-hand-side operand. (i.e. if `sizeA - sizeB -> offsetA`

, then
`offsetA + sizeB -> sizeA`

)

Subtracting an Offset from a Size returns the Size that is smaller than the Size operand by the difference given by the Offset operand. In other words, the returned Size has a width consisting of the width of the left-hand-side operand minus the Offset.dx dimension of the right-hand-side operand, and a height consisting of the height of the left-hand-side operand minus the Offset.dy dimension of the right-hand-side operand.

## Implementation

```
OffsetBase operator -(OffsetBase other) {
if (other is Size)
return Offset(width - other.width, height - other.height);
if (other is Offset)
return Size(width - other.dx, height - other.dy);
throw ArgumentError(other);
}
```