operator < method

bool operator < (OffsetBase other)

Less-than operator. Compares an Offset or Size to another Offset or Size, and returns true if both the horizontal and vertical values of the left-hand-side operand are smaller than the horizontal and vertical values of the right-hand-side operand respectively. Returns false otherwise.

This is a partial ordering. It is possible for two values to be neither less, nor greater than, nor equal to, another.

Implementation 

bool operator <(OffsetBase other) => _dx < other._dx && _dy < other._dy;